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postgres/src/backend/utils/adt/ruleutils.c
Tom Lane 0daeba0e92 Be more paranoid in ruleutils.c's get_variable(). 
We were merely Assert'ing that the Var matched the RTE it's supposedly
from.  But if the user passes incorrect information to pg_get_expr(),
the RTE might in fact not match; this led either to Assert failures
or core dumps, as reported by Chris Hanks in bug #14220.  To fix, just
convert the Asserts to test-and-elog.  Adjust an existing test-and-elog
elsewhere in the same function to be consistent in wording.

(If we really felt these were user-facing errors, we might promote them to
ereport's; but I can't convince myself that they're worth translating.)

Back-patch to 9.3; the problematic code doesn't exist before that, and
a quick check says that 9.2 doesn't crash on such cases.

Michael Paquier and Thomas Munro

Report: <20160629224349.1407.32667@wrigleys.postgresql.org>
2016-07-01 11:40:33 -04:00

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/*-------------------------------------------------------------------------
*
* ruleutils.c
* Functions to convert stored expressions/querytrees back to
* source text
*
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/utils/adt/ruleutils.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include "access/amapi.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_am.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_depend.h"
#include "catalog/pg_language.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/tlist.h"
#include "parser/parse_node.h"
#include "parser/parse_agg.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "parser/parser.h"
#include "parser/parsetree.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
#include "rewrite/rewriteSupport.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/hsearch.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
#include "utils/typcache.h"
#include "utils/xml.h"
/* ----------
* Pretty formatting constants
* ----------
*/
/* Indent counts */
#define PRETTYINDENT_STD 8
#define PRETTYINDENT_JOIN 4
#define PRETTYINDENT_VAR 4
#define PRETTYINDENT_LIMIT 40 /* wrap limit */
/* Pretty flags */
#define PRETTYFLAG_PAREN 1
#define PRETTYFLAG_INDENT 2
/* Default line length for pretty-print wrapping: 0 means wrap always */
#define WRAP_COLUMN_DEFAULT 0
/* macro to test if pretty action needed */
#define PRETTY_PAREN(context) ((context)->prettyFlags & PRETTYFLAG_PAREN)
#define PRETTY_INDENT(context) ((context)->prettyFlags & PRETTYFLAG_INDENT)
/* ----------
* Local data types
* ----------
*/
/* Context info needed for invoking a recursive querytree display routine */
typedef struct
{
StringInfo buf; /* output buffer to append to */
List *namespaces; /* List of deparse_namespace nodes */
List *windowClause; /* Current query level's WINDOW clause */
List *windowTList; /* targetlist for resolving WINDOW clause */
int prettyFlags; /* enabling of pretty-print functions */
int wrapColumn; /* max line length, or -1 for no limit */
int indentLevel; /* current indent level for prettyprint */
bool varprefix; /* TRUE to print prefixes on Vars */
ParseExprKind special_exprkind; /* set only for exprkinds needing
* special handling */
} deparse_context;
/*
* Each level of query context around a subtree needs a level of Var namespace.
* A Var having varlevelsup=N refers to the N'th item (counting from 0) in
* the current context's namespaces list.
*
* The rangetable is the list of actual RTEs from the query tree, and the
* cte list is the list of actual CTEs.
*
* rtable_names holds the alias name to be used for each RTE (either a C
* string, or NULL for nameless RTEs such as unnamed joins).
* rtable_columns holds the column alias names to be used for each RTE.
*
* In some cases we need to make names of merged JOIN USING columns unique
* across the whole query, not only per-RTE. If so, unique_using is TRUE
* and using_names is a list of C strings representing names already assigned
* to USING columns.
*
* When deparsing plan trees, there is always just a single item in the
* deparse_namespace list (since a plan tree never contains Vars with
* varlevelsup > 0). We store the PlanState node that is the immediate
* parent of the expression to be deparsed, as well as a list of that
* PlanState's ancestors. In addition, we store its outer and inner subplan
* state nodes, as well as their plan nodes' targetlists, and the index tlist
* if the current plan node might contain INDEX_VAR Vars. (These fields could
* be derived on-the-fly from the current PlanState, but it seems notationally
* clearer to set them up as separate fields.)
*/
typedef struct
{
List *rtable; /* List of RangeTblEntry nodes */
List *rtable_names; /* Parallel list of names for RTEs */
List *rtable_columns; /* Parallel list of deparse_columns structs */
List *ctes; /* List of CommonTableExpr nodes */
/* Workspace for column alias assignment: */
bool unique_using; /* Are we making USING names globally unique */
List *using_names; /* List of assigned names for USING columns */
/* Remaining fields are used only when deparsing a Plan tree: */
PlanState *planstate; /* immediate parent of current expression */
List *ancestors; /* ancestors of planstate */
PlanState *outer_planstate; /* outer subplan state, or NULL if none */
PlanState *inner_planstate; /* inner subplan state, or NULL if none */
List *outer_tlist; /* referent for OUTER_VAR Vars */
List *inner_tlist; /* referent for INNER_VAR Vars */
List *index_tlist; /* referent for INDEX_VAR Vars */
} deparse_namespace;
/*
* Per-relation data about column alias names.
*
* Selecting aliases is unreasonably complicated because of the need to dump
* rules/views whose underlying tables may have had columns added, deleted, or
* renamed since the query was parsed. We must nonetheless print the rule/view
* in a form that can be reloaded and will produce the same results as before.
*
* For each RTE used in the query, we must assign column aliases that are
* unique within that RTE. SQL does not require this of the original query,
* but due to factors such as *-expansion we need to be able to uniquely
* reference every column in a decompiled query. As long as we qualify all
* column references, per-RTE uniqueness is sufficient for that.
*
* However, we can't ensure per-column name uniqueness for unnamed join RTEs,
* since they just inherit column names from their input RTEs, and we can't
* rename the columns at the join level. Most of the time this isn't an issue
* because we don't need to reference the join's output columns as such; we
* can reference the input columns instead. That approach can fail for merged
* JOIN USING columns, however, so when we have one of those in an unnamed
* join, we have to make that column's alias globally unique across the whole
* query to ensure it can be referenced unambiguously.
*
* Another problem is that a JOIN USING clause requires the columns to be
* merged to have the same aliases in both input RTEs, and that no other
* columns in those RTEs or their children conflict with the USING names.
* To handle that, we do USING-column alias assignment in a recursive
* traversal of the query's jointree. When descending through a JOIN with
* USING, we preassign the USING column names to the child columns, overriding
* other rules for column alias assignment. We also mark each RTE with a list
* of all USING column names selected for joins containing that RTE, so that
* when we assign other columns' aliases later, we can avoid conflicts.
*
* Another problem is that if a JOIN's input tables have had columns added or
* deleted since the query was parsed, we must generate a column alias list
* for the join that matches the current set of input columns --- otherwise, a
* change in the number of columns in the left input would throw off matching
* of aliases to columns of the right input. Thus, positions in the printable
* column alias list are not necessarily one-for-one with varattnos of the
* JOIN, so we need a separate new_colnames[] array for printing purposes.
*/
typedef struct
{
/*
* colnames is an array containing column aliases to use for columns that
* existed when the query was parsed. Dropped columns have NULL entries.
* This array can be directly indexed by varattno to get a Var's name.
*
* Non-NULL entries are guaranteed unique within the RTE, *except* when
* this is for an unnamed JOIN RTE. In that case we merely copy up names
* from the two input RTEs.
*
* During the recursive descent in set_using_names(), forcible assignment
* of a child RTE's column name is represented by pre-setting that element
* of the child's colnames array. So at that stage, NULL entries in this
* array just mean that no name has been preassigned, not necessarily that
* the column is dropped.
*/
int num_cols; /* length of colnames[] array */
char **colnames; /* array of C strings and NULLs */
/*
* new_colnames is an array containing column aliases to use for columns
* that would exist if the query was re-parsed against the current
* definitions of its base tables. This is what to print as the column
* alias list for the RTE. This array does not include dropped columns,
* but it will include columns added since original parsing. Indexes in
* it therefore have little to do with current varattno values. As above,
* entries are unique unless this is for an unnamed JOIN RTE. (In such an
* RTE, we never actually print this array, but we must compute it anyway
* for possible use in computing column names of upper joins.) The
* parallel array is_new_col marks which of these columns are new since
* original parsing. Entries with is_new_col false must match the
* non-NULL colnames entries one-for-one.
*/
int num_new_cols; /* length of new_colnames[] array */
char **new_colnames; /* array of C strings */
bool *is_new_col; /* array of bool flags */
/* This flag tells whether we should actually print a column alias list */
bool printaliases;
/* This list has all names used as USING names in joins above this RTE */
List *parentUsing; /* names assigned to parent merged columns */
/*
* If this struct is for a JOIN RTE, we fill these fields during the
* set_using_names() pass to describe its relationship to its child RTEs.
*
* leftattnos and rightattnos are arrays with one entry per existing
* output column of the join (hence, indexable by join varattno). For a
* simple reference to a column of the left child, leftattnos[i] is the
* child RTE's attno and rightattnos[i] is zero; and conversely for a
* column of the right child. But for merged columns produced by JOIN
* USING/NATURAL JOIN, both leftattnos[i] and rightattnos[i] are nonzero.
* Also, if the column has been dropped, both are zero.
*
* If it's a JOIN USING, usingNames holds the alias names selected for the
* merged columns (these might be different from the original USING list,
* if we had to modify names to achieve uniqueness).
*/
int leftrti; /* rangetable index of left child */
int rightrti; /* rangetable index of right child */
int *leftattnos; /* left-child varattnos of join cols, or 0 */
int *rightattnos; /* right-child varattnos of join cols, or 0 */
List *usingNames; /* names assigned to merged columns */
} deparse_columns;
/* This macro is analogous to rt_fetch(), but for deparse_columns structs */
#define deparse_columns_fetch(rangetable_index, dpns) \
((deparse_columns *) list_nth((dpns)->rtable_columns, (rangetable_index)-1))
/*
* Entry in set_rtable_names' hash table
*/
typedef struct
{
char name[NAMEDATALEN]; /* Hash key --- must be first */
int counter; /* Largest addition used so far for name */
} NameHashEntry;
/* ----------
* Global data
* ----------
*/
static SPIPlanPtr plan_getrulebyoid = NULL;
static const char *query_getrulebyoid = "SELECT * FROM pg_catalog.pg_rewrite WHERE oid = $1";
static SPIPlanPtr plan_getviewrule = NULL;
static const char *query_getviewrule = "SELECT * FROM pg_catalog.pg_rewrite WHERE ev_class = $1 AND rulename = $2";
/* GUC parameters */
bool quote_all_identifiers = false;
/* ----------
* Local functions
*
* Most of these functions used to use fixed-size buffers to build their
* results. Now, they take an (already initialized) StringInfo object
* as a parameter, and append their text output to its contents.
* ----------
*/
static char *deparse_expression_pretty(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit,
int prettyFlags, int startIndent);
static char *pg_get_viewdef_worker(Oid viewoid,
int prettyFlags, int wrapColumn);
static char *pg_get_triggerdef_worker(Oid trigid, bool pretty);
static void decompile_column_index_array(Datum column_index_array, Oid relId,
StringInfo buf);
static char *pg_get_ruledef_worker(Oid ruleoid, int prettyFlags);
static char *pg_get_indexdef_worker(Oid indexrelid, int colno,
const Oid *excludeOps,
bool attrsOnly, bool showTblSpc,
int prettyFlags);
static char *pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
int prettyFlags);
static text *pg_get_expr_worker(text *expr, Oid relid, const char *relname,
int prettyFlags);
static int print_function_arguments(StringInfo buf, HeapTuple proctup,
bool print_table_args, bool print_defaults);
static void print_function_rettype(StringInfo buf, HeapTuple proctup);
static void print_function_trftypes(StringInfo buf, HeapTuple proctup);
static void set_rtable_names(deparse_namespace *dpns, List *parent_namespaces,
Bitmapset *rels_used);
static void set_deparse_for_query(deparse_namespace *dpns, Query *query,
List *parent_namespaces);
static void set_simple_column_names(deparse_namespace *dpns);
static bool has_dangerous_join_using(deparse_namespace *dpns, Node *jtnode);
static void set_using_names(deparse_namespace *dpns, Node *jtnode,
List *parentUsing);
static void set_relation_column_names(deparse_namespace *dpns,
RangeTblEntry *rte,
deparse_columns *colinfo);
static void set_join_column_names(deparse_namespace *dpns, RangeTblEntry *rte,
deparse_columns *colinfo);
static bool colname_is_unique(char *colname, deparse_namespace *dpns,
deparse_columns *colinfo);
static char *make_colname_unique(char *colname, deparse_namespace *dpns,
deparse_columns *colinfo);
static void expand_colnames_array_to(deparse_columns *colinfo, int n);
static void identify_join_columns(JoinExpr *j, RangeTblEntry *jrte,
deparse_columns *colinfo);
static void flatten_join_using_qual(Node *qual,
List **leftvars, List **rightvars);
static char *get_rtable_name(int rtindex, deparse_context *context);
static void set_deparse_planstate(deparse_namespace *dpns, PlanState *ps);
static void push_child_plan(deparse_namespace *dpns, PlanState *ps,
deparse_namespace *save_dpns);
static void pop_child_plan(deparse_namespace *dpns,
deparse_namespace *save_dpns);
static void push_ancestor_plan(deparse_namespace *dpns, ListCell *ancestor_cell,
deparse_namespace *save_dpns);
static void pop_ancestor_plan(deparse_namespace *dpns,
deparse_namespace *save_dpns);
static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags);
static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags, int wrapColumn);
static void get_query_def(Query *query, StringInfo buf, List *parentnamespace,
TupleDesc resultDesc,
int prettyFlags, int wrapColumn, int startIndent);
static void get_values_def(List *values_lists, deparse_context *context);
static void get_with_clause(Query *query, deparse_context *context);
static void get_select_query_def(Query *query, deparse_context *context,
TupleDesc resultDesc);
static void get_insert_query_def(Query *query, deparse_context *context);
static void get_update_query_def(Query *query, deparse_context *context);
static void get_update_query_targetlist_def(Query *query, List *targetList,
deparse_context *context,
RangeTblEntry *rte);
static void get_delete_query_def(Query *query, deparse_context *context);
static void get_utility_query_def(Query *query, deparse_context *context);
static void get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc);
static void get_target_list(List *targetList, deparse_context *context,
TupleDesc resultDesc);
static void get_setop_query(Node *setOp, Query *query,
deparse_context *context,
TupleDesc resultDesc);
static Node *get_rule_sortgroupclause(Index ref, List *tlist,
bool force_colno,
deparse_context *context);
static void get_rule_groupingset(GroupingSet *gset, List *targetlist,
bool omit_parens, deparse_context *context);
static void get_rule_orderby(List *orderList, List *targetList,
bool force_colno, deparse_context *context);
static void get_rule_windowclause(Query *query, deparse_context *context);
static void get_rule_windowspec(WindowClause *wc, List *targetList,
deparse_context *context);
static char *get_variable(Var *var, int levelsup, bool istoplevel,
deparse_context *context);
static void get_special_variable(Node *node, deparse_context *context,
void *private);
static void resolve_special_varno(Node *node, deparse_context *context,
void *private,
void (*callback) (Node *, deparse_context *, void *));
static Node *find_param_referent(Param *param, deparse_context *context,
deparse_namespace **dpns_p, ListCell **ancestor_cell_p);
static void get_parameter(Param *param, deparse_context *context);
static const char *get_simple_binary_op_name(OpExpr *expr);
static bool isSimpleNode(Node *node, Node *parentNode, int prettyFlags);
static void appendContextKeyword(deparse_context *context, const char *str,
int indentBefore, int indentAfter, int indentPlus);
static void removeStringInfoSpaces(StringInfo str);
static void get_rule_expr(Node *node, deparse_context *context,
bool showimplicit);
static void get_rule_expr_toplevel(Node *node, deparse_context *context,
bool showimplicit);
static void get_oper_expr(OpExpr *expr, deparse_context *context);
static void get_func_expr(FuncExpr *expr, deparse_context *context,
bool showimplicit);
static void get_agg_expr(Aggref *aggref, deparse_context *context,
Aggref *original_aggref);
static void get_agg_combine_expr(Node *node, deparse_context *context,
void *private);
static void get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context);
static void get_coercion_expr(Node *arg, deparse_context *context,
Oid resulttype, int32 resulttypmod,
Node *parentNode);
static void get_const_expr(Const *constval, deparse_context *context,
int showtype);
static void get_const_collation(Const *constval, deparse_context *context);
static void simple_quote_literal(StringInfo buf, const char *val);
static void get_sublink_expr(SubLink *sublink, deparse_context *context);
static void get_from_clause(Query *query, const char *prefix,
deparse_context *context);
static void get_from_clause_item(Node *jtnode, Query *query,
deparse_context *context);
static void get_column_alias_list(deparse_columns *colinfo,
deparse_context *context);
static void get_from_clause_coldeflist(RangeTblFunction *rtfunc,
deparse_columns *colinfo,
deparse_context *context);
static void get_tablesample_def(TableSampleClause *tablesample,
deparse_context *context);
static void get_opclass_name(Oid opclass, Oid actual_datatype,
StringInfo buf);
static Node *processIndirection(Node *node, deparse_context *context,
bool printit);
static void printSubscripts(ArrayRef *aref, deparse_context *context);
static char *get_relation_name(Oid relid);
static char *generate_relation_name(Oid relid, List *namespaces);
static char *generate_qualified_relation_name(Oid relid);
static char *generate_function_name(Oid funcid, int nargs,
List *argnames, Oid *argtypes,
bool has_variadic, bool *use_variadic_p,
ParseExprKind special_exprkind);
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
#define only_marker(rte) ((rte)->inh ? "" : "ONLY ")
/* ----------
* get_ruledef - Do it all and return a text
* that could be used as a statement
* to recreate the rule
* ----------
*/
Datum
pg_get_ruledef(PG_FUNCTION_ARGS)
{
Oid ruleoid = PG_GETARG_OID(0);
int prettyFlags;
prettyFlags = PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, prettyFlags)));
}
Datum
pg_get_ruledef_ext(PG_FUNCTION_ARGS)
{
Oid ruleoid = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, prettyFlags)));
}
static char *
pg_get_ruledef_worker(Oid ruleoid, int prettyFlags)
{
Datum args[1];
char nulls[1];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
StringInfoData buf;
/*
* Do this first so that string is alloc'd in outer context not SPI's.
*/
initStringInfo(&buf);
/*
* Connect to SPI manager
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* On the first call prepare the plan to lookup pg_rewrite. We read
* pg_rewrite over the SPI manager instead of using the syscache to be
* checked for read access on pg_rewrite.
*/
if (plan_getrulebyoid == NULL)
{
Oid argtypes[1];
SPIPlanPtr plan;
argtypes[0] = OIDOID;
plan = SPI_prepare(query_getrulebyoid, 1, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare failed for \"%s\"", query_getrulebyoid);
SPI_keepplan(plan);
plan_getrulebyoid = plan;
}
/*
* Get the pg_rewrite tuple for this rule
*/
args[0] = ObjectIdGetDatum(ruleoid);
nulls[0] = ' ';
spirc = SPI_execute_plan(plan_getrulebyoid, args, nulls, true, 0);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for rule %u", ruleoid);
if (SPI_processed != 1)
appendStringInfoChar(&buf, '-');
else
{
/*
* Get the rule's definition and put it into executor's memory
*/
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
make_ruledef(&buf, ruletup, rulettc, prettyFlags);
}
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
return buf.data;
}
/* ----------
* get_viewdef - Mainly the same thing, but we
* only return the SELECT part of a view
* ----------
*/
Datum
pg_get_viewdef(PG_FUNCTION_ARGS)
{
/* By OID */
Oid viewoid = PG_GETARG_OID(0);
int prettyFlags;
prettyFlags = PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT)));
}
Datum
pg_get_viewdef_ext(PG_FUNCTION_ARGS)
{
/* By OID */
Oid viewoid = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT)));
}
Datum
pg_get_viewdef_wrap(PG_FUNCTION_ARGS)
{
/* By OID */
Oid viewoid = PG_GETARG_OID(0);
int wrap = PG_GETARG_INT32(1);
int prettyFlags;
/* calling this implies we want pretty printing */
prettyFlags = PRETTYFLAG_PAREN | PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, wrap)));
}
Datum
pg_get_viewdef_name(PG_FUNCTION_ARGS)
{
/* By qualified name */
text *viewname = PG_GETARG_TEXT_P(0);
int prettyFlags;
RangeVar *viewrel;
Oid viewoid;
prettyFlags = PRETTYFLAG_INDENT;
/* Look up view name. Can't lock it - we might not have privileges. */
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname));
viewoid = RangeVarGetRelid(viewrel, NoLock, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT)));
}
Datum
pg_get_viewdef_name_ext(PG_FUNCTION_ARGS)
{
/* By qualified name */
text *viewname = PG_GETARG_TEXT_P(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
RangeVar *viewrel;
Oid viewoid;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
/* Look up view name. Can't lock it - we might not have privileges. */
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname));
viewoid = RangeVarGetRelid(viewrel, NoLock, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT)));
}
/*
* Common code for by-OID and by-name variants of pg_get_viewdef
*/
static char *
pg_get_viewdef_worker(Oid viewoid, int prettyFlags, int wrapColumn)
{
Datum args[2];
char nulls[2];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
StringInfoData buf;
/*
* Do this first so that string is alloc'd in outer context not SPI's.
*/
initStringInfo(&buf);
/*
* Connect to SPI manager
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* On the first call prepare the plan to lookup pg_rewrite. We read
* pg_rewrite over the SPI manager instead of using the syscache to be
* checked for read access on pg_rewrite.
*/
if (plan_getviewrule == NULL)
{
Oid argtypes[2];
SPIPlanPtr plan;
argtypes[0] = OIDOID;
argtypes[1] = NAMEOID;
plan = SPI_prepare(query_getviewrule, 2, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare failed for \"%s\"", query_getviewrule);
SPI_keepplan(plan);
plan_getviewrule = plan;
}
/*
* Get the pg_rewrite tuple for the view's SELECT rule
*/
args[0] = ObjectIdGetDatum(viewoid);
args[1] = DirectFunctionCall1(namein, CStringGetDatum(ViewSelectRuleName));
nulls[0] = ' ';
nulls[1] = ' ';
spirc = SPI_execute_plan(plan_getviewrule, args, nulls, true, 0);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for view %u", viewoid);
if (SPI_processed != 1)
appendStringInfoString(&buf, "Not a view");
else
{
/*
* Get the rule's definition and put it into executor's memory
*/
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
make_viewdef(&buf, ruletup, rulettc, prettyFlags, wrapColumn);
}
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
return buf.data;
}
/* ----------
* get_triggerdef - Get the definition of a trigger
* ----------
*/
Datum
pg_get_triggerdef(PG_FUNCTION_ARGS)
{
Oid trigid = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_triggerdef_worker(trigid, false)));
}
Datum
pg_get_triggerdef_ext(PG_FUNCTION_ARGS)
{
Oid trigid = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
PG_RETURN_TEXT_P(string_to_text(pg_get_triggerdef_worker(trigid, pretty)));
}
static char *
pg_get_triggerdef_worker(Oid trigid, bool pretty)
{
HeapTuple ht_trig;
Form_pg_trigger trigrec;
StringInfoData buf;
Relation tgrel;
ScanKeyData skey[1];
SysScanDesc tgscan;
int findx = 0;
char *tgname;
Oid argtypes[1]; /* dummy */
Datum value;
bool isnull;
/*
* Fetch the pg_trigger tuple by the Oid of the trigger
*/
tgrel = heap_open(TriggerRelationId, AccessShareLock);
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(trigid));
tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true,
NULL, 1, skey);
ht_trig = systable_getnext(tgscan);
if (!HeapTupleIsValid(ht_trig))
elog(ERROR, "could not find tuple for trigger %u", trigid);
trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig);
/*
* Start the trigger definition. Note that the trigger's name should never
* be schema-qualified, but the trigger rel's name may be.
*/
initStringInfo(&buf);
tgname = NameStr(trigrec->tgname);
appendStringInfo(&buf, "CREATE %sTRIGGER %s ",
OidIsValid(trigrec->tgconstraint) ? "CONSTRAINT " : "",
quote_identifier(tgname));
if (TRIGGER_FOR_BEFORE(trigrec->tgtype))
appendStringInfoString(&buf, "BEFORE");
else if (TRIGGER_FOR_AFTER(trigrec->tgtype))
appendStringInfoString(&buf, "AFTER");
else if (TRIGGER_FOR_INSTEAD(trigrec->tgtype))
appendStringInfoString(&buf, "INSTEAD OF");
else
elog(ERROR, "unexpected tgtype value: %d", trigrec->tgtype);
if (TRIGGER_FOR_INSERT(trigrec->tgtype))
{
appendStringInfoString(&buf, " INSERT");
findx++;
}
if (TRIGGER_FOR_DELETE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR DELETE");
else
appendStringInfoString(&buf, " DELETE");
findx++;
}
if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR UPDATE");
else
appendStringInfoString(&buf, " UPDATE");
findx++;
/* tgattr is first var-width field, so OK to access directly */
if (trigrec->tgattr.dim1 > 0)
{
int i;
appendStringInfoString(&buf, " OF ");
for (i = 0; i < trigrec->tgattr.dim1; i++)
{
char *attname;
if (i > 0)
appendStringInfoString(&buf, ", ");
attname = get_relid_attribute_name(trigrec->tgrelid,
trigrec->tgattr.values[i]);
appendStringInfoString(&buf, quote_identifier(attname));
}
}
}
if (TRIGGER_FOR_TRUNCATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfoString(&buf, " OR TRUNCATE");
else
appendStringInfoString(&buf, " TRUNCATE");
findx++;
}
appendStringInfo(&buf, " ON %s ",
generate_relation_name(trigrec->tgrelid, NIL));
if (OidIsValid(trigrec->tgconstraint))
{
if (OidIsValid(trigrec->tgconstrrelid))
appendStringInfo(&buf, "FROM %s ",
generate_relation_name(trigrec->tgconstrrelid, NIL));
if (!trigrec->tgdeferrable)
appendStringInfoString(&buf, "NOT ");
appendStringInfoString(&buf, "DEFERRABLE INITIALLY ");
if (trigrec->tginitdeferred)
appendStringInfoString(&buf, "DEFERRED ");
else
appendStringInfoString(&buf, "IMMEDIATE ");
}
if (TRIGGER_FOR_ROW(trigrec->tgtype))
appendStringInfoString(&buf, "FOR EACH ROW ");
else
appendStringInfoString(&buf, "FOR EACH STATEMENT ");
/* If the trigger has a WHEN qualification, add that */
value = fastgetattr(ht_trig, Anum_pg_trigger_tgqual,
tgrel->rd_att, &isnull);
if (!isnull)
{
Node *qual;
char relkind;
deparse_context context;
deparse_namespace dpns;
RangeTblEntry *oldrte;
RangeTblEntry *newrte;
appendStringInfoString(&buf, "WHEN (");
qual = stringToNode(TextDatumGetCString(value));
relkind = get_rel_relkind(trigrec->tgrelid);
/* Build minimal OLD and NEW RTEs for the rel */
oldrte = makeNode(RangeTblEntry);
oldrte->rtekind = RTE_RELATION;
oldrte->relid = trigrec->tgrelid;
oldrte->relkind = relkind;
oldrte->alias = makeAlias("old", NIL);
oldrte->eref = oldrte->alias;
oldrte->lateral = false;
oldrte->inh = false;
oldrte->inFromCl = true;
newrte = makeNode(RangeTblEntry);
newrte->rtekind = RTE_RELATION;
newrte->relid = trigrec->tgrelid;
newrte->relkind = relkind;
newrte->alias = makeAlias("new", NIL);
newrte->eref = newrte->alias;
newrte->lateral = false;
newrte->inh = false;
newrte->inFromCl = true;
/* Build two-element rtable */
memset(&dpns, 0, sizeof(dpns));
dpns.rtable = list_make2(oldrte, newrte);
dpns.ctes = NIL;
set_rtable_names(&dpns, NIL, NULL);
set_simple_column_names(&dpns);
/* Set up context with one-deep namespace stack */
context.buf = &buf;
context.namespaces = list_make1(&dpns);
context.windowClause = NIL;
context.windowTList = NIL;
context.varprefix = true;
context.prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
context.wrapColumn = WRAP_COLUMN_DEFAULT;
context.indentLevel = PRETTYINDENT_STD;
context.special_exprkind = EXPR_KIND_NONE;
get_rule_expr(qual, &context, false);
appendStringInfoString(&buf, ") ");
}
appendStringInfo(&buf, "EXECUTE PROCEDURE %s(",
generate_function_name(trigrec->tgfoid, 0,
NIL, argtypes,
false, NULL, EXPR_KIND_NONE));
if (trigrec->tgnargs > 0)
{
char *p;
int i;
value = fastgetattr(ht_trig, Anum_pg_trigger_tgargs,
tgrel->rd_att, &isnull);
if (isnull)
elog(ERROR, "tgargs is null for trigger %u", trigid);
p = (char *) VARDATA(DatumGetByteaP(value));
for (i = 0; i < trigrec->tgnargs; i++)
{
if (i > 0)
appendStringInfoString(&buf, ", ");
simple_quote_literal(&buf, p);
/* advance p to next string embedded in tgargs */
while (*p)
p++;
p++;
}
}
/* We deliberately do not put semi-colon at end */
appendStringInfoChar(&buf, ')');
/* Clean up */
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
return buf.data;
}
/* ----------
* get_indexdef - Get the definition of an index
*
* In the extended version, there is a colno argument as well as pretty bool.
* if colno == 0, we want a complete index definition.
* if colno > 0, we only want the Nth index key's variable or expression.
*
* Note that the SQL-function versions of this omit any info about the
* index tablespace; this is intentional because pg_dump wants it that way.
* However pg_get_indexdef_string() includes index tablespace if not default.
* ----------
*/
Datum
pg_get_indexdef(PG_FUNCTION_ARGS)
{
Oid indexrelid = PG_GETARG_OID(0);
int prettyFlags;
prettyFlags = PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0,
NULL,
false, false,
prettyFlags)));
}
Datum
pg_get_indexdef_ext(PG_FUNCTION_ARGS)
{
Oid indexrelid = PG_GETARG_OID(0);
int32 colno = PG_GETARG_INT32(1);
bool pretty = PG_GETARG_BOOL(2);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno,
NULL,
colno != 0,
false,
prettyFlags)));
}
/* Internal version that returns a palloc'd C string; no pretty-printing */
char *
pg_get_indexdef_string(Oid indexrelid)
{
return pg_get_indexdef_worker(indexrelid, 0, NULL, false, true, 0);
}
/* Internal version that just reports the column definitions */
char *
pg_get_indexdef_columns(Oid indexrelid, bool pretty)
{
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
return pg_get_indexdef_worker(indexrelid, 0, NULL, true, false, prettyFlags);
}
/*
* Internal workhorse to decompile an index definition.
*
* This is now used for exclusion constraints as well: if excludeOps is not
* NULL then it points to an array of exclusion operator OIDs.
*/
static char *
pg_get_indexdef_worker(Oid indexrelid, int colno,
const Oid *excludeOps,
bool attrsOnly, bool showTblSpc,
int prettyFlags)
{
/* might want a separate isConstraint parameter later */
bool isConstraint = (excludeOps != NULL);
HeapTuple ht_idx;
HeapTuple ht_idxrel;
HeapTuple ht_am;
Form_pg_index idxrec;
Form_pg_class idxrelrec;
Form_pg_am amrec;
IndexAmRoutine *amroutine;
List *indexprs;
ListCell *indexpr_item;
List *context;
Oid indrelid;
int keyno;
Datum indcollDatum;
Datum indclassDatum;
Datum indoptionDatum;
bool isnull;
oidvector *indcollation;
oidvector *indclass;
int2vector *indoption;
StringInfoData buf;
char *str;
char *sep;
/*
* Fetch the pg_index tuple by the Oid of the index
*/
ht_idx = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexrelid));
if (!HeapTupleIsValid(ht_idx))
elog(ERROR, "cache lookup failed for index %u", indexrelid);
idxrec = (Form_pg_index) GETSTRUCT(ht_idx);
indrelid = idxrec->indrelid;
Assert(indexrelid == idxrec->indexrelid);
/* Must get indcollation, indclass, and indoption the hard way */
indcollDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indcollation, &isnull);
Assert(!isnull);
indcollation = (oidvector *) DatumGetPointer(indcollDatum);
indclassDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indclass, &isnull);
Assert(!isnull);
indclass = (oidvector *) DatumGetPointer(indclassDatum);
indoptionDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indoption, &isnull);
Assert(!isnull);
indoption = (int2vector *) DatumGetPointer(indoptionDatum);
/*
* Fetch the pg_class tuple of the index relation
*/
ht_idxrel = SearchSysCache1(RELOID, ObjectIdGetDatum(indexrelid));
if (!HeapTupleIsValid(ht_idxrel))
elog(ERROR, "cache lookup failed for relation %u", indexrelid);
idxrelrec = (Form_pg_class) GETSTRUCT(ht_idxrel);
/*
* Fetch the pg_am tuple of the index' access method
*/
ht_am = SearchSysCache1(AMOID, ObjectIdGetDatum(idxrelrec->relam));
if (!HeapTupleIsValid(ht_am))
elog(ERROR, "cache lookup failed for access method %u",
idxrelrec->relam);
amrec = (Form_pg_am) GETSTRUCT(ht_am);
/* Fetch the index AM's API struct */
amroutine = GetIndexAmRoutine(amrec->amhandler);
/*
* Get the index expressions, if any. (NOTE: we do not use the relcache
* versions of the expressions and predicate, because we want to display
* non-const-folded expressions.)
*/
if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs))
{
Datum exprsDatum;
bool isnull;
char *exprsString;
exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indexprs, &isnull);
Assert(!isnull);
exprsString = TextDatumGetCString(exprsDatum);
indexprs = (List *) stringToNode(exprsString);
pfree(exprsString);
}
else
indexprs = NIL;
indexpr_item = list_head(indexprs);
context = deparse_context_for(get_relation_name(indrelid), indrelid);
/*
* Start the index definition. Note that the index's name should never be
* schema-qualified, but the indexed rel's name may be.
*/
initStringInfo(&buf);
if (!attrsOnly)
{
if (!isConstraint)
appendStringInfo(&buf, "CREATE %sINDEX %s ON %s USING %s (",
idxrec->indisunique ? "UNIQUE " : "",
quote_identifier(NameStr(idxrelrec->relname)),
generate_relation_name(indrelid, NIL),
quote_identifier(NameStr(amrec->amname)));
else /* currently, must be EXCLUDE constraint */
appendStringInfo(&buf, "EXCLUDE USING %s (",
quote_identifier(NameStr(amrec->amname)));
}
/*
* Report the indexed attributes
*/
sep = "";
for (keyno = 0; keyno < idxrec->indnatts; keyno++)
{
AttrNumber attnum = idxrec->indkey.values[keyno];
int16 opt = indoption->values[keyno];
Oid keycoltype;
Oid keycolcollation;
if (!colno)
appendStringInfoString(&buf, sep);
sep = ", ";
if (attnum != 0)
{
/* Simple index column */
char *attname;
int32 keycoltypmod;
attname = get_relid_attribute_name(indrelid, attnum);
if (!colno || colno == keyno + 1)
appendStringInfoString(&buf, quote_identifier(attname));
get_atttypetypmodcoll(indrelid, attnum,
&keycoltype, &keycoltypmod,
&keycolcollation);
}
else
{
/* expressional index */
Node *indexkey;
if (indexpr_item == NULL)
elog(ERROR, "too few entries in indexprs list");
indexkey = (Node *) lfirst(indexpr_item);
indexpr_item = lnext(indexpr_item);
/* Deparse */
str = deparse_expression_pretty(indexkey, context, false, false,
prettyFlags, 0);
if (!colno || colno == keyno + 1)
{
/* Need parens if it's not a bare function call */
if (indexkey && IsA(indexkey, FuncExpr) &&
((FuncExpr *) indexkey)->funcformat == COERCE_EXPLICIT_CALL)
appendStringInfoString(&buf, str);
else
appendStringInfo(&buf, "(%s)", str);
}
keycoltype = exprType(indexkey);
keycolcollation = exprCollation(indexkey);
}
if (!attrsOnly && (!colno || colno == keyno + 1))
{
Oid indcoll;
/* Add collation, if not default for column */
indcoll = indcollation->values[keyno];
if (OidIsValid(indcoll) && indcoll != keycolcollation)
appendStringInfo(&buf, " COLLATE %s",
generate_collation_name((indcoll)));
/* Add the operator class name, if not default */
get_opclass_name(indclass->values[keyno], keycoltype, &buf);
/* Add options if relevant */
if (amroutine->amcanorder)
{
/* if it supports sort ordering, report DESC and NULLS opts */
if (opt & INDOPTION_DESC)
{
appendStringInfoString(&buf, " DESC");
/* NULLS FIRST is the default in this case */
if (!(opt & INDOPTION_NULLS_FIRST))
appendStringInfoString(&buf, " NULLS LAST");
}
else
{
if (opt & INDOPTION_NULLS_FIRST)
appendStringInfoString(&buf, " NULLS FIRST");
}
}
/* Add the exclusion operator if relevant */
if (excludeOps != NULL)
appendStringInfo(&buf, " WITH %s",
generate_operator_name(excludeOps[keyno],
keycoltype,
keycoltype));
}
}
if (!attrsOnly)
{
appendStringInfoChar(&buf, ')');
/*
* If it has options, append "WITH (options)"
*/
str = flatten_reloptions(indexrelid);
if (str)
{
appendStringInfo(&buf, " WITH (%s)", str);
pfree(str);
}
/*
* If it's in a nondefault tablespace, say so, but only if requested
*/
if (showTblSpc)
{
Oid tblspc;
tblspc = get_rel_tablespace(indexrelid);
if (OidIsValid(tblspc))
{
if (isConstraint)
appendStringInfoString(&buf, " USING INDEX");
appendStringInfo(&buf, " TABLESPACE %s",
quote_identifier(get_tablespace_name(tblspc)));
}
}
/*
* If it's a partial index, decompile and append the predicate
*/
if (!heap_attisnull(ht_idx, Anum_pg_index_indpred))
{
Node *node;
Datum predDatum;
bool isnull;
char *predString;
/* Convert text string to node tree */
predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indpred, &isnull);
Assert(!isnull);
predString = TextDatumGetCString(predDatum);
node = (Node *) stringToNode(predString);
pfree(predString);
/* Deparse */
str = deparse_expression_pretty(node, context, false, false,
prettyFlags, 0);
if (isConstraint)
appendStringInfo(&buf, " WHERE (%s)", str);
else
appendStringInfo(&buf, " WHERE %s", str);
}
}
/* Clean up */
ReleaseSysCache(ht_idx);
ReleaseSysCache(ht_idxrel);
ReleaseSysCache(ht_am);
return buf.data;
}
/*
* pg_get_constraintdef
*
* Returns the definition for the constraint, ie, everything that needs to
* appear after "ALTER TABLE ... ADD CONSTRAINT <constraintname>".
*/
Datum
pg_get_constraintdef(PG_FUNCTION_ARGS)
{
Oid constraintId = PG_GETARG_OID(0);
int prettyFlags;
prettyFlags = PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false,
prettyFlags)));
}
Datum
pg_get_constraintdef_ext(PG_FUNCTION_ARGS)
{
Oid constraintId = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false,
prettyFlags)));
}
/*
* Internal version that returns a full ALTER TABLE ... ADD CONSTRAINT command
*/
char *
pg_get_constraintdef_command(Oid constraintId)
{
return pg_get_constraintdef_worker(constraintId, true, 0);
}
/*
* As of 9.4, we now use an MVCC snapshot for this.
*/
static char *
pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
int prettyFlags)
{
HeapTuple tup;
Form_pg_constraint conForm;
StringInfoData buf;
SysScanDesc scandesc;
ScanKeyData scankey[1];
Snapshot snapshot = RegisterSnapshot(GetTransactionSnapshot());
Relation relation = heap_open(ConstraintRelationId, AccessShareLock);
ScanKeyInit(&scankey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(constraintId));
scandesc = systable_beginscan(relation,
ConstraintOidIndexId,
true,
snapshot,
1,
scankey);
/*
* We later use the tuple with SysCacheGetAttr() as if we had obtained it
* via SearchSysCache, which works fine.
*/
tup = systable_getnext(scandesc);
UnregisterSnapshot(snapshot);
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", constraintId);
conForm = (Form_pg_constraint) GETSTRUCT(tup);
initStringInfo(&buf);
if (fullCommand)
{
/*
* Currently, callers want ALTER TABLE (without ONLY) for CHECK
* constraints, and other types of constraints don't inherit anyway so
* it doesn't matter whether we say ONLY or not. Someday we might
* need to let callers specify whether to put ONLY in the command.
*/
appendStringInfo(&buf, "ALTER TABLE %s ADD CONSTRAINT %s ",
generate_qualified_relation_name(conForm->conrelid),
quote_identifier(NameStr(conForm->conname)));
}
switch (conForm->contype)
{
case CONSTRAINT_FOREIGN:
{
Datum val;
bool isnull;
const char *string;
/* Start off the constraint definition */
appendStringInfoString(&buf, "FOREIGN KEY (");
/* Fetch and build referencing-column list */
val = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conkey, &isnull);
if (isnull)
elog(ERROR, "null conkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->conrelid, &buf);
/* add foreign relation name */
appendStringInfo(&buf, ") REFERENCES %s(",
generate_relation_name(conForm->confrelid,
NIL));
/* Fetch and build referenced-column list */
val = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_confkey, &isnull);
if (isnull)
elog(ERROR, "null confkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->confrelid, &buf);
appendStringInfoChar(&buf, ')');
/* Add match type */
switch (conForm->confmatchtype)
{
case FKCONSTR_MATCH_FULL:
string = " MATCH FULL";
break;
case FKCONSTR_MATCH_PARTIAL:
string = " MATCH PARTIAL";
break;
case FKCONSTR_MATCH_SIMPLE:
string = "";
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
conForm->confmatchtype);
string = ""; /* keep compiler quiet */
break;
}
appendStringInfoString(&buf, string);
/* Add ON UPDATE and ON DELETE clauses, if needed */
switch (conForm->confupdtype)
{
case FKCONSTR_ACTION_NOACTION:
string = NULL; /* suppress default */
break;
case FKCONSTR_ACTION_RESTRICT:
string = "RESTRICT";
break;
case FKCONSTR_ACTION_CASCADE:
string = "CASCADE";
break;
case FKCONSTR_ACTION_SETNULL:
string = "SET NULL";
break;
case FKCONSTR_ACTION_SETDEFAULT:
string = "SET DEFAULT";
break;
default:
elog(ERROR, "unrecognized confupdtype: %d",
conForm->confupdtype);
string = NULL; /* keep compiler quiet */
break;
}
if (string)
appendStringInfo(&buf, " ON UPDATE %s", string);
switch (conForm->confdeltype)
{
case FKCONSTR_ACTION_NOACTION:
string = NULL; /* suppress default */
break;
case FKCONSTR_ACTION_RESTRICT:
string = "RESTRICT";
break;
case FKCONSTR_ACTION_CASCADE:
string = "CASCADE";
break;
case FKCONSTR_ACTION_SETNULL:
string = "SET NULL";
break;
case FKCONSTR_ACTION_SETDEFAULT:
string = "SET DEFAULT";
break;
default:
elog(ERROR, "unrecognized confdeltype: %d",
conForm->confdeltype);
string = NULL; /* keep compiler quiet */
break;
}
if (string)
appendStringInfo(&buf, " ON DELETE %s", string);
break;
}
case CONSTRAINT_PRIMARY:
case CONSTRAINT_UNIQUE:
{
Datum val;
bool isnull;
Oid indexId;
/* Start off the constraint definition */
if (conForm->contype == CONSTRAINT_PRIMARY)
appendStringInfoString(&buf, "PRIMARY KEY (");
else
appendStringInfoString(&buf, "UNIQUE (");
/* Fetch and build target column list */
val = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conkey, &isnull);
if (isnull)
elog(ERROR, "null conkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->conrelid, &buf);
appendStringInfoChar(&buf, ')');
indexId = get_constraint_index(constraintId);
/* XXX why do we only print these bits if fullCommand? */
if (fullCommand && OidIsValid(indexId))
{
char *options = flatten_reloptions(indexId);
Oid tblspc;
if (options)
{
appendStringInfo(&buf, " WITH (%s)", options);
pfree(options);
}
tblspc = get_rel_tablespace(indexId);
if (OidIsValid(tblspc))
appendStringInfo(&buf, " USING INDEX TABLESPACE %s",
quote_identifier(get_tablespace_name(tblspc)));
}
break;
}
case CONSTRAINT_CHECK:
{
Datum val;
bool isnull;
char *conbin;
char *consrc;
Node *expr;
List *context;
/* Fetch constraint expression in parsetree form */
val = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conbin, &isnull);
if (isnull)
elog(ERROR, "null conbin for constraint %u",
constraintId);
conbin = TextDatumGetCString(val);
expr = stringToNode(conbin);
/* Set up deparsing context for Var nodes in constraint */
if (conForm->conrelid != InvalidOid)
{
/* relation constraint */
context = deparse_context_for(get_relation_name(conForm->conrelid),
conForm->conrelid);
}
else
{
/* domain constraint --- can't have Vars */
context = NIL;
}
consrc = deparse_expression_pretty(expr, context, false, false,
prettyFlags, 0);
/*
* Now emit the constraint definition, adding NO INHERIT if
* necessary.
*
* There are cases where the constraint expression will be
* fully parenthesized and we don't need the outer parens ...
* but there are other cases where we do need 'em. Be
* conservative for now.
*
* Note that simply checking for leading '(' and trailing ')'
* would NOT be good enough, consider "(x > 0) AND (y > 0)".
*/
appendStringInfo(&buf, "CHECK (%s)%s",
consrc,
conForm->connoinherit ? " NO INHERIT" : "");
break;
}
case CONSTRAINT_TRIGGER:
/*
* There isn't an ALTER TABLE syntax for creating a user-defined
* constraint trigger, but it seems better to print something than
* throw an error; if we throw error then this function couldn't
* safely be applied to all rows of pg_constraint.
*/
appendStringInfoString(&buf, "TRIGGER");
break;
case CONSTRAINT_EXCLUSION:
{
Oid indexOid = conForm->conindid;
Datum val;
bool isnull;
Datum *elems;
int nElems;
int i;
Oid *operators;
/* Extract operator OIDs from the pg_constraint tuple */
val = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conexclop,
&isnull);
if (isnull)
elog(ERROR, "null conexclop for constraint %u",
constraintId);
deconstruct_array(DatumGetArrayTypeP(val),
OIDOID, sizeof(Oid), true, 'i',
&elems, NULL, &nElems);
operators = (Oid *) palloc(nElems * sizeof(Oid));
for (i = 0; i < nElems; i++)
operators[i] = DatumGetObjectId(elems[i]);
/* pg_get_indexdef_worker does the rest */
/* suppress tablespace because pg_dump wants it that way */
appendStringInfoString(&buf,
pg_get_indexdef_worker(indexOid,
0,
operators,
false,
false,
prettyFlags));
break;
}
default:
elog(ERROR, "invalid constraint type \"%c\"", conForm->contype);
break;
}
if (conForm->condeferrable)
appendStringInfoString(&buf, " DEFERRABLE");
if (conForm->condeferred)
appendStringInfoString(&buf, " INITIALLY DEFERRED");
if (!conForm->convalidated)
appendStringInfoString(&buf, " NOT VALID");
/* Cleanup */
systable_endscan(scandesc);
heap_close(relation, AccessShareLock);
return buf.data;
}
/*
* Convert an int16[] Datum into a comma-separated list of column names
* for the indicated relation; append the list to buf.
*/
static void
decompile_column_index_array(Datum column_index_array, Oid relId,
StringInfo buf)
{
Datum *keys;
int nKeys;
int j;
/* Extract data from array of int16 */
deconstruct_array(DatumGetArrayTypeP(column_index_array),
INT2OID, 2, true, 's',
&keys, NULL, &nKeys);
for (j = 0; j < nKeys; j++)
{
char *colName;
colName = get_relid_attribute_name(relId, DatumGetInt16(keys[j]));
if (j == 0)
appendStringInfoString(buf, quote_identifier(colName));
else
appendStringInfo(buf, ", %s", quote_identifier(colName));
}
}
/* ----------
* get_expr - Decompile an expression tree
*
* Input: an expression tree in nodeToString form, and a relation OID
*
* Output: reverse-listed expression
*
* Currently, the expression can only refer to a single relation, namely
* the one specified by the second parameter. This is sufficient for
* partial indexes, column default expressions, etc. We also support
* Var-free expressions, for which the OID can be InvalidOid.
* ----------
*/
Datum
pg_get_expr(PG_FUNCTION_ARGS)
{
text *expr = PG_GETARG_TEXT_P(0);
Oid relid = PG_GETARG_OID(1);
int prettyFlags;
char *relname;
prettyFlags = PRETTYFLAG_INDENT;
if (OidIsValid(relid))
{
/* Get the name for the relation */
relname = get_rel_name(relid);
/*
* If the OID isn't actually valid, don't throw an error, just return
* NULL. This is a bit questionable, but it's what we've done
* historically, and it can help avoid unwanted failures when
* examining catalog entries for just-deleted relations.
*/
if (relname == NULL)
PG_RETURN_NULL();
}
else
relname = NULL;
PG_RETURN_TEXT_P(pg_get_expr_worker(expr, relid, relname, prettyFlags));
}
Datum
pg_get_expr_ext(PG_FUNCTION_ARGS)
{
text *expr = PG_GETARG_TEXT_P(0);
Oid relid = PG_GETARG_OID(1);
bool pretty = PG_GETARG_BOOL(2);
int prettyFlags;
char *relname;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT;
if (OidIsValid(relid))
{
/* Get the name for the relation */
relname = get_rel_name(relid);
/* See notes above */
if (relname == NULL)
PG_RETURN_NULL();
}
else
relname = NULL;
PG_RETURN_TEXT_P(pg_get_expr_worker(expr, relid, relname, prettyFlags));
}
static text *
pg_get_expr_worker(text *expr, Oid relid, const char *relname, int prettyFlags)
{
Node *node;
List *context;
char *exprstr;
char *str;
/* Convert input TEXT object to C string */
exprstr = text_to_cstring(expr);
/* Convert expression to node tree */
node = (Node *) stringToNode(exprstr);
pfree(exprstr);
/* Prepare deparse context if needed */
if (OidIsValid(relid))
context = deparse_context_for(relname, relid);
else
context = NIL;
/* Deparse */
str = deparse_expression_pretty(node, context, false, false,
prettyFlags, 0);
return string_to_text(str);
}
/* ----------
* get_userbyid - Get a user name by roleid and
* fallback to 'unknown (OID=n)'
* ----------
*/
Datum
pg_get_userbyid(PG_FUNCTION_ARGS)
{
Oid roleid = PG_GETARG_OID(0);
Name result;
HeapTuple roletup;
Form_pg_authid role_rec;
/*
* Allocate space for the result
*/
result = (Name) palloc(NAMEDATALEN);
memset(NameStr(*result), 0, NAMEDATALEN);
/*
* Get the pg_authid entry and print the result
*/
roletup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
if (HeapTupleIsValid(roletup))
{
role_rec = (Form_pg_authid) GETSTRUCT(roletup);
StrNCpy(NameStr(*result), NameStr(role_rec->rolname), NAMEDATALEN);
ReleaseSysCache(roletup);
}
else
sprintf(NameStr(*result), "unknown (OID=%u)", roleid);
PG_RETURN_NAME(result);
}
/*
* pg_get_serial_sequence
* Get the name of the sequence used by a serial column,
* formatted suitably for passing to setval, nextval or currval.
* First parameter is not treated as double-quoted, second parameter
* is --- see documentation for reason.
*/
Datum
pg_get_serial_sequence(PG_FUNCTION_ARGS)
{
text *tablename = PG_GETARG_TEXT_P(0);
text *columnname = PG_GETARG_TEXT_PP(1);
RangeVar *tablerv;
Oid tableOid;
char *column;
AttrNumber attnum;
Oid sequenceId = InvalidOid;
Relation depRel;
ScanKeyData key[3];
SysScanDesc scan;
HeapTuple tup;
/* Look up table name. Can't lock it - we might not have privileges. */
tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename));
tableOid = RangeVarGetRelid(tablerv, NoLock, false);
/* Get the number of the column */
column = text_to_cstring(columnname);
attnum = get_attnum(tableOid, column);
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
column, tablerv->relname)));
/* Search the dependency table for the dependent sequence */
depRel = heap_open(DependRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(tableOid));
ScanKeyInit(&key[2],
Anum_pg_depend_refobjsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(attnum));
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
NULL, 3, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
/*
* We assume any auto dependency of a sequence on a column must be
* what we are looking for. (We need the relkind test because indexes
* can also have auto dependencies on columns.)
*/
if (deprec->classid == RelationRelationId &&
deprec->objsubid == 0 &&
deprec->deptype == DEPENDENCY_AUTO &&
get_rel_relkind(deprec->objid) == RELKIND_SEQUENCE)
{
sequenceId = deprec->objid;
break;
}
}
systable_endscan(scan);
heap_close(depRel, AccessShareLock);
if (OidIsValid(sequenceId))
{
char *result;
result = generate_qualified_relation_name(sequenceId);
PG_RETURN_TEXT_P(string_to_text(result));
}
PG_RETURN_NULL();
}
/*
* pg_get_functiondef
* Returns the complete "CREATE OR REPLACE FUNCTION ..." statement for
* the specified function.
*
* Note: if you change the output format of this function, be careful not
* to break psql's rules (in \ef and \sf) for identifying the start of the
* function body. To wit: the function body starts on a line that begins
* with "AS ", and no preceding line will look like that.
*/
Datum
pg_get_functiondef(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
StringInfoData buf;
StringInfoData dq;
HeapTuple proctup;
Form_pg_proc proc;
Datum tmp;
bool isnull;
const char *prosrc;
const char *name;
const char *nsp;
float4 procost;
int oldlen;
initStringInfo(&buf);
/* Look up the function */
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
proc = (Form_pg_proc) GETSTRUCT(proctup);
name = NameStr(proc->proname);
if (proc->proisagg)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is an aggregate function", name)));
/*
* We always qualify the function name, to ensure the right function gets
* replaced.
*/
nsp = get_namespace_name(proc->pronamespace);
appendStringInfo(&buf, "CREATE OR REPLACE FUNCTION %s(",
quote_qualified_identifier(nsp, name));
(void) print_function_arguments(&buf, proctup, false, true);
appendStringInfoString(&buf, ")\n RETURNS ");
print_function_rettype(&buf, proctup);
print_function_trftypes(&buf, proctup);
appendStringInfo(&buf, "\n LANGUAGE %s\n",
quote_identifier(get_language_name(proc->prolang, false)));
/* Emit some miscellaneous options on one line */
oldlen = buf.len;
if (proc->proiswindow)
appendStringInfoString(&buf, " WINDOW");
switch (proc->provolatile)
{
case PROVOLATILE_IMMUTABLE:
appendStringInfoString(&buf, " IMMUTABLE");
break;
case PROVOLATILE_STABLE:
appendStringInfoString(&buf, " STABLE");
break;
case PROVOLATILE_VOLATILE:
break;
}
switch (proc->proparallel)
{
case PROPARALLEL_SAFE:
appendStringInfoString(&buf, " PARALLEL SAFE");
break;
case PROPARALLEL_RESTRICTED:
appendStringInfoString(&buf, " PARALLEL RESTRICTED");
break;
case PROPARALLEL_UNSAFE:
break;
}
if (proc->proisstrict)
appendStringInfoString(&buf, " STRICT");
if (proc->prosecdef)
appendStringInfoString(&buf, " SECURITY DEFINER");
if (proc->proleakproof)
appendStringInfoString(&buf, " LEAKPROOF");
/* This code for the default cost and rows should match functioncmds.c */
if (proc->prolang == INTERNALlanguageId ||
proc->prolang == ClanguageId)
procost = 1;
else
procost = 100;
if (proc->procost != procost)
appendStringInfo(&buf, " COST %g", proc->procost);
if (proc->prorows > 0 && proc->prorows != 1000)
appendStringInfo(&buf, " ROWS %g", proc->prorows);
if (oldlen != buf.len)
appendStringInfoChar(&buf, '\n');
/* Emit any proconfig options, one per line */
tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proconfig, &isnull);
if (!isnull)
{
ArrayType *a = DatumGetArrayTypeP(tmp);
int i;
Assert(ARR_ELEMTYPE(a) == TEXTOID);
Assert(ARR_NDIM(a) == 1);
Assert(ARR_LBOUND(a)[0] == 1);
for (i = 1; i <= ARR_DIMS(a)[0]; i++)
{
Datum d;
d = array_ref(a, 1, &i,
-1 /* varlenarray */ ,
-1 /* TEXT's typlen */ ,
false /* TEXT's typbyval */ ,
'i' /* TEXT's typalign */ ,
&isnull);
if (!isnull)
{
char *configitem = TextDatumGetCString(d);
char *pos;
pos = strchr(configitem, '=');
if (pos == NULL)
continue;
*pos++ = '\0';
appendStringInfo(&buf, " SET %s TO ",
quote_identifier(configitem));
/*
* Some GUC variable names are 'LIST' type and hence must not
* be quoted.
*/
if (pg_strcasecmp(configitem, "DateStyle") == 0
|| pg_strcasecmp(configitem, "search_path") == 0)
appendStringInfoString(&buf, pos);
else
simple_quote_literal(&buf, pos);
appendStringInfoChar(&buf, '\n');
}
}
}
/* And finally the function definition ... */
appendStringInfoString(&buf, "AS ");
tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_probin, &isnull);
if (!isnull)
{
simple_quote_literal(&buf, TextDatumGetCString(tmp));
appendStringInfoString(&buf, ", "); /* assume prosrc isn't null */
}
tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_prosrc, &isnull);
if (isnull)
elog(ERROR, "null prosrc");
prosrc = TextDatumGetCString(tmp);
/*
* We always use dollar quoting. Figure out a suitable delimiter.
*
* Since the user is likely to be editing the function body string, we
* shouldn't use a short delimiter that he might easily create a conflict
* with. Hence prefer "$function$", but extend if needed.
*/
initStringInfo(&dq);
appendStringInfoString(&dq, "$function");
while (strstr(prosrc, dq.data) != NULL)
appendStringInfoChar(&dq, 'x');
appendStringInfoChar(&dq, '$');
appendStringInfoString(&buf, dq.data);
appendStringInfoString(&buf, prosrc);
appendStringInfoString(&buf, dq.data);
appendStringInfoChar(&buf, '\n');
ReleaseSysCache(proctup);
PG_RETURN_TEXT_P(string_to_text(buf.data));
}
/*
* pg_get_function_arguments
* Get a nicely-formatted list of arguments for a function.
* This is everything that would go between the parentheses in
* CREATE FUNCTION.
*/
Datum
pg_get_function_arguments(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
StringInfoData buf;
HeapTuple proctup;
initStringInfo(&buf);
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
(void) print_function_arguments(&buf, proctup, false, true);
ReleaseSysCache(proctup);
PG_RETURN_TEXT_P(string_to_text(buf.data));
}
/*
* pg_get_function_identity_arguments
* Get a formatted list of arguments for a function.
* This is everything that would go between the parentheses in
* ALTER FUNCTION, etc. In particular, don't print defaults.
*/
Datum
pg_get_function_identity_arguments(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
StringInfoData buf;
HeapTuple proctup;
initStringInfo(&buf);
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
(void) print_function_arguments(&buf, proctup, false, false);
ReleaseSysCache(proctup);
PG_RETURN_TEXT_P(string_to_text(buf.data));
}
/*
* pg_get_function_result
* Get a nicely-formatted version of the result type of a function.
* This is what would appear after RETURNS in CREATE FUNCTION.
*/
Datum
pg_get_function_result(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
StringInfoData buf;
HeapTuple proctup;
initStringInfo(&buf);
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
print_function_rettype(&buf, proctup);
ReleaseSysCache(proctup);
PG_RETURN_TEXT_P(string_to_text(buf.data));
}
/*
* Guts of pg_get_function_result: append the function's return type
* to the specified buffer.
*/
static void
print_function_rettype(StringInfo buf, HeapTuple proctup)
{
Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(proctup);
int ntabargs = 0;
StringInfoData rbuf;
initStringInfo(&rbuf);
if (proc->proretset)
{
/* It might be a table function; try to print the arguments */
appendStringInfoString(&rbuf, "TABLE(");
ntabargs = print_function_arguments(&rbuf, proctup, true, false);
if (ntabargs > 0)
appendStringInfoChar(&rbuf, ')');
else
resetStringInfo(&rbuf);
}
if (ntabargs == 0)
{
/* Not a table function, so do the normal thing */
if (proc->proretset)
appendStringInfoString(&rbuf, "SETOF ");
appendStringInfoString(&rbuf, format_type_be(proc->prorettype));
}
appendStringInfoString(buf, rbuf.data);
}
/*
* Common code for pg_get_function_arguments and pg_get_function_result:
* append the desired subset of arguments to buf. We print only TABLE
* arguments when print_table_args is true, and all the others when it's false.
* We print argument defaults only if print_defaults is true.
* Function return value is the number of arguments printed.
*/
static int
print_function_arguments(StringInfo buf, HeapTuple proctup,
bool print_table_args, bool print_defaults)
{
Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(proctup);
int numargs;
Oid *argtypes;
char **argnames;
char *argmodes;
int insertorderbyat = -1;
int argsprinted;
int inputargno;
int nlackdefaults;
ListCell *nextargdefault = NULL;
int i;
numargs = get_func_arg_info(proctup,
&argtypes, &argnames, &argmodes);
nlackdefaults = numargs;
if (print_defaults && proc->pronargdefaults > 0)
{
Datum proargdefaults;
bool isnull;
proargdefaults = SysCacheGetAttr(PROCOID, proctup,
Anum_pg_proc_proargdefaults,
&isnull);
if (!isnull)
{
char *str;
List *argdefaults;
str = TextDatumGetCString(proargdefaults);
argdefaults = (List *) stringToNode(str);
Assert(IsA(argdefaults, List));
pfree(str);
nextargdefault = list_head(argdefaults);
/* nlackdefaults counts only *input* arguments lacking defaults */
nlackdefaults = proc->pronargs - list_length(argdefaults);
}
}
/* Check for special treatment of ordered-set aggregates */
if (proc->proisagg)
{
HeapTuple aggtup;
Form_pg_aggregate agg;
aggtup = SearchSysCache1(AGGFNOID,
ObjectIdGetDatum(HeapTupleGetOid(proctup)));
if (!HeapTupleIsValid(aggtup))
elog(ERROR, "cache lookup failed for aggregate %u",
HeapTupleGetOid(proctup));
agg = (Form_pg_aggregate) GETSTRUCT(aggtup);
if (AGGKIND_IS_ORDERED_SET(agg->aggkind))
insertorderbyat = agg->aggnumdirectargs;
ReleaseSysCache(aggtup);
}
argsprinted = 0;
inputargno = 0;
for (i = 0; i < numargs; i++)
{
Oid argtype = argtypes[i];
char *argname = argnames ? argnames[i] : NULL;
char argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
const char *modename;
bool isinput;
switch (argmode)
{
case PROARGMODE_IN:
modename = "";
isinput = true;
break;
case PROARGMODE_INOUT:
modename = "INOUT ";
isinput = true;
break;
case PROARGMODE_OUT:
modename = "OUT ";
isinput = false;
break;
case PROARGMODE_VARIADIC:
modename = "VARIADIC ";
isinput = true;
break;
case PROARGMODE_TABLE:
modename = "";
isinput = false;
break;
default:
elog(ERROR, "invalid parameter mode '%c'", argmode);
modename = NULL; /* keep compiler quiet */
isinput = false;
break;
}
if (isinput)
inputargno++; /* this is a 1-based counter */
if (print_table_args != (argmode == PROARGMODE_TABLE))
continue;
if (argsprinted == insertorderbyat)
{
if (argsprinted)
appendStringInfoChar(buf, ' ');
appendStringInfoString(buf, "ORDER BY ");
}
else if (argsprinted)
appendStringInfoString(buf, ", ");
appendStringInfoString(buf, modename);
if (argname && argname[0])
appendStringInfo(buf, "%s ", quote_identifier(argname));
appendStringInfoString(buf, format_type_be(argtype));
if (print_defaults && isinput && inputargno > nlackdefaults)
{
Node *expr;
Assert(nextargdefault != NULL);
expr = (Node *) lfirst(nextargdefault);
nextargdefault = lnext(nextargdefault);
appendStringInfo(buf, " DEFAULT %s",
deparse_expression(expr, NIL, false, false));
}
argsprinted++;
/* nasty hack: print the last arg twice for variadic ordered-set agg */
if (argsprinted == insertorderbyat && i == numargs - 1)
{
i--;
/* aggs shouldn't have defaults anyway, but just to be sure ... */
print_defaults = false;
}
}
return argsprinted;
}
static bool
is_input_argument(int nth, const char *argmodes)
{
return (!argmodes
|| argmodes[nth] == PROARGMODE_IN
|| argmodes[nth] == PROARGMODE_INOUT
|| argmodes[nth] == PROARGMODE_VARIADIC);
}
/*
* Append used transformated types to specified buffer
*/
static void
print_function_trftypes(StringInfo buf, HeapTuple proctup)
{
Oid *trftypes;
int ntypes;
ntypes = get_func_trftypes(proctup, &trftypes);
if (ntypes > 0)
{
int i;
appendStringInfoString(buf, "\n TRANSFORM ");
for (i = 0; i < ntypes; i++)
{
if (i != 0)
appendStringInfoString(buf, ", ");
appendStringInfo(buf, "FOR TYPE %s", format_type_be(trftypes[i]));
}
}
}
/*
* Get textual representation of a function argument's default value. The
* second argument of this function is the argument number among all arguments
* (i.e. proallargtypes, *not* proargtypes), starting with 1, because that's
* how information_schema.sql uses it.
*/
Datum
pg_get_function_arg_default(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
int32 nth_arg = PG_GETARG_INT32(1);
HeapTuple proctup;
Form_pg_proc proc;
int numargs;
Oid *argtypes;
char **argnames;
char *argmodes;
int i;
List *argdefaults;
Node *node;
char *str;
int nth_inputarg;
Datum proargdefaults;
bool isnull;
int nth_default;
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
numargs = get_func_arg_info(proctup, &argtypes, &argnames, &argmodes);
if (nth_arg < 1 || nth_arg > numargs || !is_input_argument(nth_arg - 1, argmodes))
{
ReleaseSysCache(proctup);
PG_RETURN_NULL();
}
nth_inputarg = 0;
for (i = 0; i < nth_arg; i++)
if (is_input_argument(i, argmodes))
nth_inputarg++;
proargdefaults = SysCacheGetAttr(PROCOID, proctup,
Anum_pg_proc_proargdefaults,
&isnull);
if (isnull)
{
ReleaseSysCache(proctup);
PG_RETURN_NULL();
}
str = TextDatumGetCString(proargdefaults);
argdefaults = (List *) stringToNode(str);
Assert(IsA(argdefaults, List));
pfree(str);
proc = (Form_pg_proc) GETSTRUCT(proctup);
/*
* Calculate index into proargdefaults: proargdefaults corresponds to the
* last N input arguments, where N = pronargdefaults.
*/
nth_default = nth_inputarg - 1 - (proc->pronargs - proc->pronargdefaults);
if (nth_default < 0 || nth_default >= list_length(argdefaults))
{
ReleaseSysCache(proctup);
PG_RETURN_NULL();
}
node = list_nth(argdefaults, nth_default);
str = deparse_expression(node, NIL, false, false);
ReleaseSysCache(proctup);
PG_RETURN_TEXT_P(string_to_text(str));
}
/*
* deparse_expression - General utility for deparsing expressions
*
* calls deparse_expression_pretty with all prettyPrinting disabled
*/
char *
deparse_expression(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit)
{
return deparse_expression_pretty(expr, dpcontext, forceprefix,
showimplicit, 0, 0);
}
/* ----------
* deparse_expression_pretty - General utility for deparsing expressions
*
* expr is the node tree to be deparsed. It must be a transformed expression
* tree (ie, not the raw output of gram.y).
*
* dpcontext is a list of deparse_namespace nodes representing the context
* for interpreting Vars in the node tree. It can be NIL if no Vars are
* expected.
*
* forceprefix is TRUE to force all Vars to be prefixed with their table names.
*
* showimplicit is TRUE to force all implicit casts to be shown explicitly.
*
* Tries to pretty up the output according to prettyFlags and startIndent.
*
* The result is a palloc'd string.
* ----------
*/
static char *
deparse_expression_pretty(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit,
int prettyFlags, int startIndent)
{
StringInfoData buf;
deparse_context context;
initStringInfo(&buf);
context.buf = &buf;
context.namespaces = dpcontext;
context.windowClause = NIL;
context.windowTList = NIL;
context.varprefix = forceprefix;
context.prettyFlags = prettyFlags;
context.wrapColumn = WRAP_COLUMN_DEFAULT;
context.indentLevel = startIndent;
context.special_exprkind = EXPR_KIND_NONE;
get_rule_expr(expr, &context, showimplicit);
return buf.data;
}
/* ----------
* deparse_context_for - Build deparse context for a single relation
*
* Given the reference name (alias) and OID of a relation, build deparsing
* context for an expression referencing only that relation (as varno 1,
* varlevelsup 0). This is sufficient for many uses of deparse_expression.
* ----------
*/
List *
deparse_context_for(const char *aliasname, Oid relid)
{
deparse_namespace *dpns;
RangeTblEntry *rte;
dpns = (deparse_namespace *) palloc0(sizeof(deparse_namespace));
/* Build a minimal RTE for the rel */
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = relid;
rte->relkind = RELKIND_RELATION; /* no need for exactness here */
rte->alias = makeAlias(aliasname, NIL);
rte->eref = rte->alias;
rte->lateral = false;
rte->inh = false;
rte->inFromCl = true;
/* Build one-element rtable */
dpns->rtable = list_make1(rte);
dpns->ctes = NIL;
set_rtable_names(dpns, NIL, NULL);
set_simple_column_names(dpns);
/* Return a one-deep namespace stack */
return list_make1(dpns);
}
/*
* deparse_context_for_plan_rtable - Build deparse context for a plan's rtable
*
* When deparsing an expression in a Plan tree, we use the plan's rangetable
* to resolve names of simple Vars. The initialization of column names for
* this is rather expensive if the rangetable is large, and it'll be the same
* for every expression in the Plan tree; so we do it just once and re-use
* the result of this function for each expression. (Note that the result
* is not usable until set_deparse_context_planstate() is applied to it.)
*
* In addition to the plan's rangetable list, pass the per-RTE alias names
* assigned by a previous call to select_rtable_names_for_explain.
*/
List *
deparse_context_for_plan_rtable(List *rtable, List *rtable_names)
{
deparse_namespace *dpns;
dpns = (deparse_namespace *) palloc0(sizeof(deparse_namespace));
/* Initialize fields that stay the same across the whole plan tree */
dpns->rtable = rtable;
dpns->rtable_names = rtable_names;
dpns->ctes = NIL;
/*
* Set up column name aliases. We will get rather bogus results for join
* RTEs, but that doesn't matter because plan trees don't contain any join
* alias Vars.
*/
set_simple_column_names(dpns);
/* Return a one-deep namespace stack */
return list_make1(dpns);
}
/*
* set_deparse_context_planstate - Specify Plan node containing expression
*
* When deparsing an expression in a Plan tree, we might have to resolve
* OUTER_VAR, INNER_VAR, or INDEX_VAR references. To do this, the caller must
* provide the parent PlanState node. Then OUTER_VAR and INNER_VAR references
* can be resolved by drilling down into the left and right child plans.
* Similarly, INDEX_VAR references can be resolved by reference to the
* indextlist given in a parent IndexOnlyScan node, or to the scan tlist in
* ForeignScan and CustomScan nodes. (Note that we don't currently support
* deparsing of indexquals in regular IndexScan or BitmapIndexScan nodes;
* for those, we can only deparse the indexqualorig fields, which won't
* contain INDEX_VAR Vars.)
*
* Note: planstate really ought to be declared as "PlanState *", but we use
* "Node *" to avoid having to include execnodes.h in ruleutils.h.
*
* The ancestors list is a list of the PlanState's parent PlanStates, the
* most-closely-nested first. This is needed to resolve PARAM_EXEC Params.
* Note we assume that all the PlanStates share the same rtable.
*
* Once this function has been called, deparse_expression() can be called on
* subsidiary expression(s) of the specified PlanState node. To deparse
* expressions of a different Plan node in the same Plan tree, re-call this
* function to identify the new parent Plan node.
*
* The result is the same List passed in; this is a notational convenience.
*/
List *
set_deparse_context_planstate(List *dpcontext,
Node *planstate, List *ancestors)
{
deparse_namespace *dpns;
/* Should always have one-entry namespace list for Plan deparsing */
Assert(list_length(dpcontext) == 1);
dpns = (deparse_namespace *) linitial(dpcontext);
/* Set our attention on the specific plan node passed in */
set_deparse_planstate(dpns, (PlanState *) planstate);
dpns->ancestors = ancestors;
return dpcontext;
}
/*
* select_rtable_names_for_explain - Select RTE aliases for EXPLAIN
*
* Determine the relation aliases we'll use during an EXPLAIN operation.
* This is just a frontend to set_rtable_names. We have to expose the aliases
* to EXPLAIN because EXPLAIN needs to know the right alias names to print.
*/
List *
select_rtable_names_for_explain(List *rtable, Bitmapset *rels_used)
{
deparse_namespace dpns;
memset(&dpns, 0, sizeof(dpns));
dpns.rtable = rtable;
dpns.ctes = NIL;
set_rtable_names(&dpns, NIL, rels_used);
/* We needn't bother computing column aliases yet */
return dpns.rtable_names;
}
/*
* set_rtable_names: select RTE aliases to be used in printing a query
*
* We fill in dpns->rtable_names with a list of names that is one-for-one with
* the already-filled dpns->rtable list. Each RTE name is unique among those
* in the new namespace plus any ancestor namespaces listed in
* parent_namespaces.
*
* If rels_used isn't NULL, only RTE indexes listed in it are given aliases.
*
* Note that this function is only concerned with relation names, not column
* names.
*/
static void
set_rtable_names(deparse_namespace *dpns, List *parent_namespaces,
Bitmapset *rels_used)
{
HASHCTL hash_ctl;
HTAB *names_hash;
NameHashEntry *hentry;
bool found;
int rtindex;
ListCell *lc;
dpns->rtable_names = NIL;
/* nothing more to do if empty rtable */
if (dpns->rtable == NIL)
return;
/*
* We use a hash table to hold known names, so that this process is O(N)
* not O(N^2) for N names.
*/
MemSet(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = NAMEDATALEN;
hash_ctl.entrysize = sizeof(NameHashEntry);
hash_ctl.hcxt = CurrentMemoryContext;
names_hash = hash_create("set_rtable_names names",
list_length(dpns->rtable),
&hash_ctl,
HASH_ELEM | HASH_CONTEXT);
/* Preload the hash table with names appearing in parent_namespaces */
foreach(lc, parent_namespaces)
{
deparse_namespace *olddpns = (deparse_namespace *) lfirst(lc);
ListCell *lc2;
foreach(lc2, olddpns->rtable_names)
{
char *oldname = (char *) lfirst(lc2);
if (oldname == NULL)
continue;
hentry = (NameHashEntry *) hash_search(names_hash,
oldname,
HASH_ENTER,
&found);
/* we do not complain about duplicate names in parent namespaces */
hentry->counter = 0;
}
}
/* Now we can scan the rtable */
rtindex = 1;
foreach(lc, dpns->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
char *refname;
/* Just in case this takes an unreasonable amount of time ... */
CHECK_FOR_INTERRUPTS();
if (rels_used && !bms_is_member(rtindex, rels_used))
{
/* Ignore unreferenced RTE */
refname = NULL;
}
else if (rte->alias)
{
/* If RTE has a user-defined alias, prefer that */
refname = rte->alias->aliasname;
}
else if (rte->rtekind == RTE_RELATION)
{
/* Use the current actual name of the relation */
refname = get_rel_name(rte->relid);
}
else if (rte->rtekind == RTE_JOIN)
{
/* Unnamed join has no refname */
refname = NULL;
}
else
{
/* Otherwise use whatever the parser assigned */
refname = rte->eref->aliasname;
}
/*
* If the selected name isn't unique, append digits to make it so, and
* make a new hash entry for it once we've got a unique name. For a
* very long input name, we might have to truncate to stay within
* NAMEDATALEN.
*/
if (refname)
{
hentry = (NameHashEntry *) hash_search(names_hash,
refname,
HASH_ENTER,
&found);
if (found)
{
/* Name already in use, must choose a new one */
int refnamelen = strlen(refname);
char *modname = (char *) palloc(refnamelen + 16);
NameHashEntry *hentry2;
do
{
hentry->counter++;
for (;;)
{
/*
* We avoid using %.*s here because it can misbehave
* if the data is not valid in what libc thinks is the
* prevailing encoding.
*/
memcpy(modname, refname, refnamelen);
sprintf(modname + refnamelen, "_%d", hentry->counter);
if (strlen(modname) < NAMEDATALEN)
break;
/* drop chars from refname to keep all the digits */
refnamelen = pg_mbcliplen(refname, refnamelen,
refnamelen - 1);
}
hentry2 = (NameHashEntry *) hash_search(names_hash,
modname,
HASH_ENTER,
&found);
} while (found);
hentry2->counter = 0; /* init new hash entry */
refname = modname;
}
else
{
/* Name not previously used, need only initialize hentry */
hentry->counter = 0;
}
}
dpns->rtable_names = lappend(dpns->rtable_names, refname);
rtindex++;
}
hash_destroy(names_hash);
}
/*
* set_deparse_for_query: set up deparse_namespace for deparsing a Query tree
*
* For convenience, this is defined to initialize the deparse_namespace struct
* from scratch.
*/
static void
set_deparse_for_query(deparse_namespace *dpns, Query *query,
List *parent_namespaces)
{
ListCell *lc;
ListCell *lc2;
/* Initialize *dpns and fill rtable/ctes links */
memset(dpns, 0, sizeof(deparse_namespace));
dpns->rtable = query->rtable;
dpns->ctes = query->cteList;
/* Assign a unique relation alias to each RTE */
set_rtable_names(dpns, parent_namespaces, NULL);
/* Initialize dpns->rtable_columns to contain zeroed structs */
dpns->rtable_columns = NIL;
while (list_length(dpns->rtable_columns) < list_length(dpns->rtable))
dpns->rtable_columns = lappend(dpns->rtable_columns,
palloc0(sizeof(deparse_columns)));
/* If it's a utility query, it won't have a jointree */
if (query->jointree)
{
/* Detect whether global uniqueness of USING names is needed */
dpns->unique_using =
has_dangerous_join_using(dpns, (Node *) query->jointree);
/*
* Select names for columns merged by USING, via a recursive pass over
* the query jointree.
*/
set_using_names(dpns, (Node *) query->jointree, NIL);
}
/*
* Now assign remaining column aliases for each RTE. We do this in a
* linear scan of the rtable, so as to process RTEs whether or not they
* are in the jointree (we mustn't miss NEW.*, INSERT target relations,
* etc). JOIN RTEs must be processed after their children, but this is
* okay because they appear later in the rtable list than their children
* (cf Asserts in identify_join_columns()).
*/
forboth(lc, dpns->rtable, lc2, dpns->rtable_columns)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
deparse_columns *colinfo = (deparse_columns *) lfirst(lc2);
if (rte->rtekind == RTE_JOIN)
set_join_column_names(dpns, rte, colinfo);
else
set_relation_column_names(dpns, rte, colinfo);
}
}
/*
* set_simple_column_names: fill in column aliases for non-query situations
*
* This handles EXPLAIN and cases where we only have relation RTEs. Without
* a join tree, we can't do anything smart about join RTEs, but we don't
* need to (note that EXPLAIN should never see join alias Vars anyway).
* If we do hit a join RTE we'll just process it like a non-table base RTE.
*/
static void
set_simple_column_names(deparse_namespace *dpns)
{
ListCell *lc;
ListCell *lc2;
/* Initialize dpns->rtable_columns to contain zeroed structs */
dpns->rtable_columns = NIL;
while (list_length(dpns->rtable_columns) < list_length(dpns->rtable))
dpns->rtable_columns = lappend(dpns->rtable_columns,
palloc0(sizeof(deparse_columns)));
/* Assign unique column aliases within each RTE */
forboth(lc, dpns->rtable, lc2, dpns->rtable_columns)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
deparse_columns *colinfo = (deparse_columns *) lfirst(lc2);
set_relation_column_names(dpns, rte, colinfo);
}
}
/*
* has_dangerous_join_using: search jointree for unnamed JOIN USING
*
* Merged columns of a JOIN USING may act differently from either of the input
* columns, either because they are merged with COALESCE (in a FULL JOIN) or
* because an implicit coercion of the underlying input column is required.
* In such a case the column must be referenced as a column of the JOIN not as
* a column of either input. And this is problematic if the join is unnamed
* (alias-less): we cannot qualify the column's name with an RTE name, since
* there is none. (Forcibly assigning an alias to the join is not a solution,
* since that will prevent legal references to tables below the join.)
* To ensure that every column in the query is unambiguously referenceable,
* we must assign such merged columns names that are globally unique across
* the whole query, aliasing other columns out of the way as necessary.
*
* Because the ensuing re-aliasing is fairly damaging to the readability of
* the query, we don't do this unless we have to. So, we must pre-scan
* the join tree to see if we have to, before starting set_using_names().
*/
static bool
has_dangerous_join_using(deparse_namespace *dpns, Node *jtnode)
{
if (IsA(jtnode, RangeTblRef))
{
/* nothing to do here */
}
else if (IsA(jtnode, FromExpr))
{
FromExpr *f = (FromExpr *) jtnode;
ListCell *lc;
foreach(lc, f->fromlist)
{
if (has_dangerous_join_using(dpns, (Node *) lfirst(lc)))
return true;
}
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
/* Is it an unnamed JOIN with USING? */
if (j->alias == NULL && j->usingClause)
{
/*
* Yes, so check each join alias var to see if any of them are not
* simple references to underlying columns. If so, we have a
* dangerous situation and must pick unique aliases.
*/
RangeTblEntry *jrte = rt_fetch(j->rtindex, dpns->rtable);
ListCell *lc;
foreach(lc, jrte->joinaliasvars)
{
Var *aliasvar = (Var *) lfirst(lc);
if (aliasvar != NULL && !IsA(aliasvar, Var))
return true;
}
}
/* Nope, but inspect children */
if (has_dangerous_join_using(dpns, j->larg))
return true;
if (has_dangerous_join_using(dpns, j->rarg))
return true;
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
return false;
}
/*
* set_using_names: select column aliases to be used for merged USING columns
*
* We do this during a recursive descent of the query jointree.
* dpns->unique_using must already be set to determine the global strategy.
*
* Column alias info is saved in the dpns->rtable_columns list, which is
* assumed to be filled with pre-zeroed deparse_columns structs.
*
* parentUsing is a list of all USING aliases assigned in parent joins of
* the current jointree node. (The passed-in list must not be modified.)
*/
static void
set_using_names(deparse_namespace *dpns, Node *jtnode, List *parentUsing)
{
if (IsA(jtnode, RangeTblRef))
{
/* nothing to do now */
}
else if (IsA(jtnode, FromExpr))
{
FromExpr *f = (FromExpr *) jtnode;
ListCell *lc;
foreach(lc, f->fromlist)
set_using_names(dpns, (Node *) lfirst(lc), parentUsing);
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
RangeTblEntry *rte = rt_fetch(j->rtindex, dpns->rtable);
deparse_columns *colinfo = deparse_columns_fetch(j->rtindex, dpns);
int *leftattnos;
int *rightattnos;
deparse_columns *leftcolinfo;
deparse_columns *rightcolinfo;
int i;
ListCell *lc;
/* Get info about the shape of the join */
identify_join_columns(j, rte, colinfo);
leftattnos = colinfo->leftattnos;
rightattnos = colinfo->rightattnos;
/* Look up the not-yet-filled-in child deparse_columns structs */
leftcolinfo = deparse_columns_fetch(colinfo->leftrti, dpns);
rightcolinfo = deparse_columns_fetch(colinfo->rightrti, dpns);
/*
* If this join is unnamed, then we cannot substitute new aliases at
* this level, so any name requirements pushed down to here must be
* pushed down again to the children.
*/
if (rte->alias == NULL)
{
for (i = 0; i < colinfo->num_cols; i++)
{
char *colname = colinfo->colnames[i];
if (colname == NULL)
continue;
/* Push down to left column, unless it's a system column */
if (leftattnos[i] > 0)
{
expand_colnames_array_to(leftcolinfo, leftattnos[i]);
leftcolinfo->colnames[leftattnos[i] - 1] = colname;
}
/* Same on the righthand side */
if (rightattnos[i] > 0)
{
expand_colnames_array_to(rightcolinfo, rightattnos[i]);
rightcolinfo->colnames[rightattnos[i] - 1] = colname;
}
}
}
/*
* If there's a USING clause, select the USING column names and push
* those names down to the children. We have two strategies:
*
* If dpns->unique_using is TRUE, we force all USING names to be
* unique across the whole query level. In principle we'd only need
* the names of dangerous USING columns to be globally unique, but to
* safely assign all USING names in a single pass, we have to enforce
* the same uniqueness rule for all of them. However, if a USING
* column's name has been pushed down from the parent, we should use
* it as-is rather than making a uniqueness adjustment. This is
* necessary when we're at an unnamed join, and it creates no risk of
* ambiguity. Also, if there's a user-written output alias for a
* merged column, we prefer to use that rather than the input name;
* this simplifies the logic and seems likely to lead to less aliasing
* overall.
*
* If dpns->unique_using is FALSE, we only need USING names to be
* unique within their own join RTE. We still need to honor
* pushed-down names, though.
*
* Though significantly different in results, these two strategies are
* implemented by the same code, with only the difference of whether
* to put assigned names into dpns->using_names.
*/
if (j->usingClause)
{
/* Copy the input parentUsing list so we don't modify it */
parentUsing = list_copy(parentUsing);
/* USING names must correspond to the first join output columns */
expand_colnames_array_to(colinfo, list_length(j->usingClause));
i = 0;
foreach(lc, j->usingClause)
{
char *colname = strVal(lfirst(lc));
/* Assert it's a merged column */
Assert(leftattnos[i] != 0 && rightattnos[i] != 0);
/* Adopt passed-down name if any, else select unique name */
if (colinfo->colnames[i] != NULL)
colname = colinfo->colnames[i];
else
{
/* Prefer user-written output alias if any */
if (rte->alias && i < list_length(rte->alias->colnames))
colname = strVal(list_nth(rte->alias->colnames, i));
/* Make it appropriately unique */
colname = make_colname_unique(colname, dpns, colinfo);
if (dpns->unique_using)
dpns->using_names = lappend(dpns->using_names,
colname);
/* Save it as output column name, too */
colinfo->colnames[i] = colname;
}
/* Remember selected names for use later */
colinfo->usingNames = lappend(colinfo->usingNames, colname);
parentUsing = lappend(parentUsing, colname);
/* Push down to left column, unless it's a system column */
if (leftattnos[i] > 0)
{
expand_colnames_array_to(leftcolinfo, leftattnos[i]);
leftcolinfo->colnames[leftattnos[i] - 1] = colname;
}
/* Same on the righthand side */
if (rightattnos[i] > 0)
{
expand_colnames_array_to(rightcolinfo, rightattnos[i]);
rightcolinfo->colnames[rightattnos[i] - 1] = colname;
}
i++;
}
}
/* Mark child deparse_columns structs with correct parentUsing info */
leftcolinfo->parentUsing = parentUsing;
rightcolinfo->parentUsing = parentUsing;
/* Now recursively assign USING column names in children */
set_using_names(dpns, j->larg, parentUsing);
set_using_names(dpns, j->rarg, parentUsing);
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
}
/*
* set_relation_column_names: select column aliases for a non-join RTE
*
* Column alias info is saved in *colinfo, which is assumed to be pre-zeroed.
* If any colnames entries are already filled in, those override local
* choices.
*/
static void
set_relation_column_names(deparse_namespace *dpns, RangeTblEntry *rte,
deparse_columns *colinfo)
{
int ncolumns;
char **real_colnames;
bool changed_any;
int noldcolumns;
int i;
int j;
/*
* Extract the RTE's "real" column names. This is comparable to
* get_rte_attribute_name, except that it's important to disregard dropped
* columns. We put NULL into the array for a dropped column.
*/
if (rte->rtekind == RTE_RELATION)
{
/* Relation --- look to the system catalogs for up-to-date info */
Relation rel;
TupleDesc tupdesc;
rel = relation_open(rte->relid, AccessShareLock);
tupdesc = RelationGetDescr(rel);
ncolumns = tupdesc->natts;
real_colnames = (char **) palloc(ncolumns * sizeof(char *));
for (i = 0; i < ncolumns; i++)
{
if (tupdesc->attrs[i]->attisdropped)
real_colnames[i] = NULL;
else
real_colnames[i] = pstrdup(NameStr(tupdesc->attrs[i]->attname));
}
relation_close(rel, AccessShareLock);
}
else
{
/* Otherwise use the column names from eref */
ListCell *lc;
ncolumns = list_length(rte->eref->colnames);
real_colnames = (char **) palloc(ncolumns * sizeof(char *));
i = 0;
foreach(lc, rte->eref->colnames)
{
/*
* If the column name shown in eref is an empty string, then it's
* a column that was dropped at the time of parsing the query, so
* treat it as dropped.
*/
char *cname = strVal(lfirst(lc));
if (cname[0] == '\0')
cname = NULL;
real_colnames[i] = cname;
i++;
}
}
/*
* Ensure colinfo->colnames has a slot for each column. (It could be long
* enough already, if we pushed down a name for the last column.) Note:
* it's possible that there are now more columns than there were when the
* query was parsed, ie colnames could be longer than rte->eref->colnames.
* We must assign unique aliases to the new columns too, else there could
* be unresolved conflicts when the view/rule is reloaded.
*/
expand_colnames_array_to(colinfo, ncolumns);
Assert(colinfo->num_cols == ncolumns);
/*
* Make sufficiently large new_colnames and is_new_col arrays, too.
*
* Note: because we leave colinfo->num_new_cols zero until after the loop,
* colname_is_unique will not consult that array, which is fine because it
* would only be duplicate effort.
*/
colinfo->new_colnames = (char **) palloc(ncolumns * sizeof(char *));
colinfo->is_new_col = (bool *) palloc(ncolumns * sizeof(bool));
/*
* Scan the columns, select a unique alias for each one, and store it in
* colinfo->colnames and colinfo->new_colnames. The former array has NULL
* entries for dropped columns, the latter omits them. Also mark
* new_colnames entries as to whether they are new since parse time; this
* is the case for entries beyond the length of rte->eref->colnames.
*/
noldcolumns = list_length(rte->eref->colnames);
changed_any = false;
j = 0;
for (i = 0; i < ncolumns; i++)
{
char *real_colname = real_colnames[i];
char *colname = colinfo->colnames[i];
/* Skip dropped columns */
if (real_colname == NULL)
{
Assert(colname == NULL); /* colnames[i] is already NULL */
continue;
}
/* If alias already assigned, that's what to use */
if (colname == NULL)
{
/* If user wrote an alias, prefer that over real column name */
if (rte->alias && i < list_length(rte->alias->colnames))
colname = strVal(list_nth(rte->alias->colnames, i));
else
colname = real_colname;
/* Unique-ify and insert into colinfo */
colname = make_colname_unique(colname, dpns, colinfo);
colinfo->colnames[i] = colname;
}
/* Put names of non-dropped columns in new_colnames[] too */
colinfo->new_colnames[j] = colname;
/* And mark them as new or not */
colinfo->is_new_col[j] = (i >= noldcolumns);
j++;
/* Remember if any assigned aliases differ from "real" name */
if (!changed_any && strcmp(colname, real_colname) != 0)
changed_any = true;
}
/*
* Set correct length for new_colnames[] array. (Note: if columns have
* been added, colinfo->num_cols includes them, which is not really quite
* right but is harmless, since any new columns must be at the end where
* they won't affect varattnos of pre-existing columns.)
*/
colinfo->num_new_cols = j;
/*
* For a relation RTE, we need only print the alias column names if any
* are different from the underlying "real" names. For a function RTE,
* always emit a complete column alias list; this is to protect against
* possible instability of the default column names (eg, from altering
* parameter names). For other RTE types, print if we changed anything OR
* if there were user-written column aliases (since the latter would be
* part of the underlying "reality").
*/
if (rte->rtekind == RTE_RELATION)
colinfo->printaliases = changed_any;
else if (rte->rtekind == RTE_FUNCTION)
colinfo->printaliases = true;
else if (rte->alias && rte->alias->colnames != NIL)
colinfo->printaliases = true;
else
colinfo->printaliases = changed_any;
}
/*
* set_join_column_names: select column aliases for a join RTE
*
* Column alias info is saved in *colinfo, which is assumed to be pre-zeroed.
* If any colnames entries are already filled in, those override local
* choices. Also, names for USING columns were already chosen by
* set_using_names(). We further expect that column alias selection has been
* completed for both input RTEs.
*/
static void
set_join_column_names(deparse_namespace *dpns, RangeTblEntry *rte,
deparse_columns *colinfo)
{
deparse_columns *leftcolinfo;
deparse_columns *rightcolinfo;
bool changed_any;
int noldcolumns;
int nnewcolumns;
Bitmapset *leftmerged = NULL;
Bitmapset *rightmerged = NULL;
int i;
int j;
int ic;
int jc;
/* Look up the previously-filled-in child deparse_columns structs */
leftcolinfo = deparse_columns_fetch(colinfo->leftrti, dpns);
rightcolinfo = deparse_columns_fetch(colinfo->rightrti, dpns);
/*
* Ensure colinfo->colnames has a slot for each column. (It could be long
* enough already, if we pushed down a name for the last column.) Note:
* it's possible that one or both inputs now have more columns than there
* were when the query was parsed, but we'll deal with that below. We
* only need entries in colnames for pre-existing columns.
*/
noldcolumns = list_length(rte->eref->colnames);
expand_colnames_array_to(colinfo, noldcolumns);
Assert(colinfo->num_cols == noldcolumns);
/*
* Scan the join output columns, select an alias for each one, and store
* it in colinfo->colnames. If there are USING columns, set_using_names()
* already selected their names, so we can start the loop at the first
* non-merged column.
*/
changed_any = false;
for (i = list_length(colinfo->usingNames); i < noldcolumns; i++)
{
char *colname = colinfo->colnames[i];
char *real_colname;
/* Ignore dropped column (only possible for non-merged column) */
if (colinfo->leftattnos[i] == 0 && colinfo->rightattnos[i] == 0)
{
Assert(colname == NULL);
continue;
}
/* Get the child column name */
if (colinfo->leftattnos[i] > 0)
real_colname = leftcolinfo->colnames[colinfo->leftattnos[i] - 1];
else if (colinfo->rightattnos[i] > 0)
real_colname = rightcolinfo->colnames[colinfo->rightattnos[i] - 1];
else
{
/* We're joining system columns --- use eref name */
real_colname = strVal(list_nth(rte->eref->colnames, i));
}
Assert(real_colname != NULL);
/* In an unnamed join, just report child column names as-is */
if (rte->alias == NULL)
{
colinfo->colnames[i] = real_colname;
continue;
}
/* If alias already assigned, that's what to use */
if (colname == NULL)
{
/* If user wrote an alias, prefer that over real column name */
if (rte->alias && i < list_length(rte->alias->colnames))
colname = strVal(list_nth(rte->alias->colnames, i));
else
colname = real_colname;
/* Unique-ify and insert into colinfo */
colname = make_colname_unique(colname, dpns, colinfo);
colinfo->colnames[i] = colname;
}
/* Remember if any assigned aliases differ from "real" name */
if (!changed_any && strcmp(colname, real_colname) != 0)
changed_any = true;
}
/*
* Calculate number of columns the join would have if it were re-parsed
* now, and create storage for the new_colnames and is_new_col arrays.
*
* Note: colname_is_unique will be consulting new_colnames[] during the
* loops below, so its not-yet-filled entries must be zeroes.
*/
nnewcolumns = leftcolinfo->num_new_cols + rightcolinfo->num_new_cols -
list_length(colinfo->usingNames);
colinfo->num_new_cols = nnewcolumns;
colinfo->new_colnames = (char **) palloc0(nnewcolumns * sizeof(char *));
colinfo->is_new_col = (bool *) palloc0(nnewcolumns * sizeof(bool));
/*
* Generating the new_colnames array is a bit tricky since any new columns
* added since parse time must be inserted in the right places. This code
* must match the parser, which will order a join's columns as merged
* columns first (in USING-clause order), then non-merged columns from the
* left input (in attnum order), then non-merged columns from the right
* input (ditto). If one of the inputs is itself a join, its columns will
* be ordered according to the same rule, which means newly-added columns
* might not be at the end. We can figure out what's what by consulting
* the leftattnos and rightattnos arrays plus the input is_new_col arrays.
*
* In these loops, i indexes leftattnos/rightattnos (so it's join varattno
* less one), j indexes new_colnames/is_new_col, and ic/jc have similar
* meanings for the current child RTE.
*/
/* Handle merged columns; they are first and can't be new */
i = j = 0;
while (i < noldcolumns &&
colinfo->leftattnos[i] != 0 &&
colinfo->rightattnos[i] != 0)
{
/* column name is already determined and known unique */
colinfo->new_colnames[j] = colinfo->colnames[i];
colinfo->is_new_col[j] = false;
/* build bitmapsets of child attnums of merged columns */
if (colinfo->leftattnos[i] > 0)
leftmerged = bms_add_member(leftmerged, colinfo->leftattnos[i]);
if (colinfo->rightattnos[i] > 0)
rightmerged = bms_add_member(rightmerged, colinfo->rightattnos[i]);
i++, j++;
}
/* Handle non-merged left-child columns */
ic = 0;
for (jc = 0; jc < leftcolinfo->num_new_cols; jc++)
{
char *child_colname = leftcolinfo->new_colnames[jc];
if (!leftcolinfo->is_new_col[jc])
{
/* Advance ic to next non-dropped old column of left child */
while (ic < leftcolinfo->num_cols &&
leftcolinfo->colnames[ic] == NULL)
ic++;
Assert(ic < leftcolinfo->num_cols);
ic++;
/* If it is a merged column, we already processed it */
if (bms_is_member(ic, leftmerged))
continue;
/* Else, advance i to the corresponding existing join column */
while (i < colinfo->num_cols &&
colinfo->colnames[i] == NULL)
i++;
Assert(i < colinfo->num_cols);
Assert(ic == colinfo->leftattnos[i]);
/* Use the already-assigned name of this column */
colinfo->new_colnames[j] = colinfo->colnames[i];
i++;
}
else
{
/*
* Unique-ify the new child column name and assign, unless we're
* in an unnamed join, in which case just copy
*/
if (rte->alias != NULL)
{
colinfo->new_colnames[j] =
make_colname_unique(child_colname, dpns, colinfo);
if (!changed_any &&
strcmp(colinfo->new_colnames[j], child_colname) != 0)
changed_any = true;
}
else
colinfo->new_colnames[j] = child_colname;
}
colinfo->is_new_col[j] = leftcolinfo->is_new_col[jc];
j++;
}
/* Handle non-merged right-child columns in exactly the same way */
ic = 0;
for (jc = 0; jc < rightcolinfo->num_new_cols; jc++)
{
char *child_colname = rightcolinfo->new_colnames[jc];
if (!rightcolinfo->is_new_col[jc])
{
/* Advance ic to next non-dropped old column of right child */
while (ic < rightcolinfo->num_cols &&
rightcolinfo->colnames[ic] == NULL)
ic++;
Assert(ic < rightcolinfo->num_cols);
ic++;
/* If it is a merged column, we already processed it */
if (bms_is_member(ic, rightmerged))
continue;
/* Else, advance i to the corresponding existing join column */
while (i < colinfo->num_cols &&
colinfo->colnames[i] == NULL)
i++;
Assert(i < colinfo->num_cols);
Assert(ic == colinfo->rightattnos[i]);
/* Use the already-assigned name of this column */
colinfo->new_colnames[j] = colinfo->colnames[i];
i++;
}
else
{
/*
* Unique-ify the new child column name and assign, unless we're
* in an unnamed join, in which case just copy
*/
if (rte->alias != NULL)
{
colinfo->new_colnames[j] =
make_colname_unique(child_colname, dpns, colinfo);
if (!changed_any &&
strcmp(colinfo->new_colnames[j], child_colname) != 0)
changed_any = true;
}
else
colinfo->new_colnames[j] = child_colname;
}
colinfo->is_new_col[j] = rightcolinfo->is_new_col[jc];
j++;
}
/* Assert we processed the right number of columns */
#ifdef USE_ASSERT_CHECKING
while (i < colinfo->num_cols && colinfo->colnames[i] == NULL)
i++;
Assert(i == colinfo->num_cols);
Assert(j == nnewcolumns);
#endif
/*
* For a named join, print column aliases if we changed any from the child
* names. Unnamed joins cannot print aliases.
*/
if (rte->alias != NULL)
colinfo->printaliases = changed_any;
else
colinfo->printaliases = false;
}
/*
* colname_is_unique: is colname distinct from already-chosen column names?
*
* dpns is query-wide info, colinfo is for the column's RTE
*/
static bool
colname_is_unique(char *colname, deparse_namespace *dpns,
deparse_columns *colinfo)
{
int i;
ListCell *lc;
/* Check against already-assigned column aliases within RTE */
for (i = 0; i < colinfo->num_cols; i++)
{
char *oldname = colinfo->colnames[i];
if (oldname && strcmp(oldname, colname) == 0)
return false;
}
/*
* If we're building a new_colnames array, check that too (this will be
* partially but not completely redundant with the previous checks)
*/
for (i = 0; i < colinfo->num_new_cols; i++)
{
char *oldname = colinfo->new_colnames[i];
if (oldname && strcmp(oldname, colname) == 0)
return false;
}
/* Also check against USING-column names that must be globally unique */
foreach(lc, dpns->using_names)
{
char *oldname = (char *) lfirst(lc);
if (strcmp(oldname, colname) == 0)
return false;
}
/* Also check against names already assigned for parent-join USING cols */
foreach(lc, colinfo->parentUsing)
{
char *oldname = (char *) lfirst(lc);
if (strcmp(oldname, colname) == 0)
return false;
}
return true;
}
/*
* make_colname_unique: modify colname if necessary to make it unique
*
* dpns is query-wide info, colinfo is for the column's RTE
*/
static char *
make_colname_unique(char *colname, deparse_namespace *dpns,
deparse_columns *colinfo)
{
/*
* If the selected name isn't unique, append digits to make it so. For a
* very long input name, we might have to truncate to stay within
* NAMEDATALEN.
*/
if (!colname_is_unique(colname, dpns, colinfo))
{
int colnamelen = strlen(colname);
char *modname = (char *) palloc(colnamelen + 16);
int i = 0;
do
{
i++;
for (;;)
{
/*
* We avoid using %.*s here because it can misbehave if the
* data is not valid in what libc thinks is the prevailing
* encoding.
*/
memcpy(modname, colname, colnamelen);
sprintf(modname + colnamelen, "_%d", i);
if (strlen(modname) < NAMEDATALEN)
break;
/* drop chars from colname to keep all the digits */
colnamelen = pg_mbcliplen(colname, colnamelen,
colnamelen - 1);
}
} while (!colname_is_unique(modname, dpns, colinfo));
colname = modname;
}
return colname;
}
/*
* expand_colnames_array_to: make colinfo->colnames at least n items long
*
* Any added array entries are initialized to zero.
*/
static void
expand_colnames_array_to(deparse_columns *colinfo, int n)
{
if (n > colinfo->num_cols)
{
if (colinfo->colnames == NULL)
colinfo->colnames = (char **) palloc0(n * sizeof(char *));
else
{
colinfo->colnames = (char **) repalloc(colinfo->colnames,
n * sizeof(char *));
memset(colinfo->colnames + colinfo->num_cols, 0,
(n - colinfo->num_cols) * sizeof(char *));
}
colinfo->num_cols = n;
}
}
/*
* identify_join_columns: figure out where columns of a join come from
*
* Fills the join-specific fields of the colinfo struct, except for
* usingNames which is filled later.
*/
static void
identify_join_columns(JoinExpr *j, RangeTblEntry *jrte,
deparse_columns *colinfo)
{
int numjoincols;
int i;
ListCell *lc;
/* Extract left/right child RT indexes */
if (IsA(j->larg, RangeTblRef))
colinfo->leftrti = ((RangeTblRef *) j->larg)->rtindex;
else if (IsA(j->larg, JoinExpr))
colinfo->leftrti = ((JoinExpr *) j->larg)->rtindex;
else
elog(ERROR, "unrecognized node type in jointree: %d",
(int) nodeTag(j->larg));
if (IsA(j->rarg, RangeTblRef))
colinfo->rightrti = ((RangeTblRef *) j->rarg)->rtindex;
else if (IsA(j->rarg, JoinExpr))
colinfo->rightrti = ((JoinExpr *) j->rarg)->rtindex;
else
elog(ERROR, "unrecognized node type in jointree: %d",
(int) nodeTag(j->rarg));
/* Assert children will be processed earlier than join in second pass */
Assert(colinfo->leftrti < j->rtindex);
Assert(colinfo->rightrti < j->rtindex);
/* Initialize result arrays with zeroes */
numjoincols = list_length(jrte->joinaliasvars);
Assert(numjoincols == list_length(jrte->eref->colnames));
colinfo->leftattnos = (int *) palloc0(numjoincols * sizeof(int));
colinfo->rightattnos = (int *) palloc0(numjoincols * sizeof(int));
/* Scan the joinaliasvars list to identify simple column references */
i = 0;
foreach(lc, jrte->joinaliasvars)
{
Var *aliasvar = (Var *) lfirst(lc);
/* get rid of any implicit coercion above the Var */
aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar);
if (aliasvar == NULL)
{
/* It's a dropped column; nothing to do here */
}
else if (IsA(aliasvar, Var))
{
Assert(aliasvar->varlevelsup == 0);
Assert(aliasvar->varattno != 0);
if (aliasvar->varno == colinfo->leftrti)
colinfo->leftattnos[i] = aliasvar->varattno;
else if (aliasvar->varno == colinfo->rightrti)
colinfo->rightattnos[i] = aliasvar->varattno;
else
elog(ERROR, "unexpected varno %d in JOIN RTE",
aliasvar->varno);
}
else if (IsA(aliasvar, CoalesceExpr))
{
/*
* It's a merged column in FULL JOIN USING. Ignore it for now and
* let the code below identify the merged columns.
*/
}
else
elog(ERROR, "unrecognized node type in join alias vars: %d",
(int) nodeTag(aliasvar));
i++;
}
/*
* If there's a USING clause, deconstruct the join quals to identify the
* merged columns. This is a tad painful but if we cannot rely on the
* column names, there is no other representation of which columns were
* joined by USING. (Unless the join type is FULL, we can't tell from the
* joinaliasvars list which columns are merged.) Note: we assume that the
* merged columns are the first output column(s) of the join.
*/
if (j->usingClause)
{
List *leftvars = NIL;
List *rightvars = NIL;
ListCell *lc2;
/* Extract left- and right-side Vars from the qual expression */
flatten_join_using_qual(j->quals, &leftvars, &rightvars);
Assert(list_length(leftvars) == list_length(j->usingClause));
Assert(list_length(rightvars) == list_length(j->usingClause));
/* Mark the output columns accordingly */
i = 0;
forboth(lc, leftvars, lc2, rightvars)
{
Var *leftvar = (Var *) lfirst(lc);
Var *rightvar = (Var *) lfirst(lc2);
Assert(leftvar->varlevelsup == 0);
Assert(leftvar->varattno != 0);
if (leftvar->varno != colinfo->leftrti)
elog(ERROR, "unexpected varno %d in JOIN USING qual",
leftvar->varno);
colinfo->leftattnos[i] = leftvar->varattno;
Assert(rightvar->varlevelsup == 0);
Assert(rightvar->varattno != 0);
if (rightvar->varno != colinfo->rightrti)
elog(ERROR, "unexpected varno %d in JOIN USING qual",
rightvar->varno);
colinfo->rightattnos[i] = rightvar->varattno;
i++;
}
}
}
/*
* flatten_join_using_qual: extract Vars being joined from a JOIN/USING qual
*
* We assume that transformJoinUsingClause won't have produced anything except
* AND nodes, equality operator nodes, and possibly implicit coercions, and
* that the AND node inputs match left-to-right with the original USING list.
*
* Caller must initialize the result lists to NIL.
*/
static void
flatten_join_using_qual(Node *qual, List **leftvars, List **rightvars)
{
if (IsA(qual, BoolExpr))
{
/* Handle AND nodes by recursion */
BoolExpr *b = (BoolExpr *) qual;
ListCell *lc;
Assert(b->boolop == AND_EXPR);
foreach(lc, b->args)
{
flatten_join_using_qual((Node *) lfirst(lc),
leftvars, rightvars);
}
}
else if (IsA(qual, OpExpr))
{
/* Otherwise we should have an equality operator */
OpExpr *op = (OpExpr *) qual;
Var *var;
if (list_length(op->args) != 2)
elog(ERROR, "unexpected unary operator in JOIN/USING qual");
/* Arguments should be Vars with perhaps implicit coercions */
var = (Var *) strip_implicit_coercions((Node *) linitial(op->args));
if (!IsA(var, Var))
elog(ERROR, "unexpected node type in JOIN/USING qual: %d",
(int) nodeTag(var));
*leftvars = lappend(*leftvars, var);
var = (Var *) strip_implicit_coercions((Node *) lsecond(op->args));
if (!IsA(var, Var))
elog(ERROR, "unexpected node type in JOIN/USING qual: %d",
(int) nodeTag(var));
*rightvars = lappend(*rightvars, var);
}
else
{
/* Perhaps we have an implicit coercion to boolean? */
Node *q = strip_implicit_coercions(qual);
if (q != qual)
flatten_join_using_qual(q, leftvars, rightvars);
else
elog(ERROR, "unexpected node type in JOIN/USING qual: %d",
(int) nodeTag(qual));
}
}
/*
* get_rtable_name: convenience function to get a previously assigned RTE alias
*
* The RTE must belong to the topmost namespace level in "context".
*/
static char *
get_rtable_name(int rtindex, deparse_context *context)
{
deparse_namespace *dpns = (deparse_namespace *) linitial(context->namespaces);
Assert(rtindex > 0 && rtindex <= list_length(dpns->rtable_names));
return (char *) list_nth(dpns->rtable_names, rtindex - 1);
}
/*
* set_deparse_planstate: set up deparse_namespace to parse subexpressions
* of a given PlanState node
*
* This sets the planstate, outer_planstate, inner_planstate, outer_tlist,
* inner_tlist, and index_tlist fields. Caller is responsible for adjusting
* the ancestors list if necessary. Note that the rtable and ctes fields do
* not need to change when shifting attention to different plan nodes in a
* single plan tree.
*/
static void
set_deparse_planstate(deparse_namespace *dpns, PlanState *ps)
{
dpns->planstate = ps;
/*
* We special-case Append and MergeAppend to pretend that the first child
* plan is the OUTER referent; we have to interpret OUTER Vars in their
* tlists according to one of the children, and the first one is the most
* natural choice. Likewise special-case ModifyTable to pretend that the
* first child plan is the OUTER referent; this is to support RETURNING
* lists containing references to non-target relations.
*/
if (IsA(ps, AppendState))
dpns->outer_planstate = ((AppendState *) ps)->appendplans[0];
else if (IsA(ps, MergeAppendState))
dpns->outer_planstate = ((MergeAppendState *) ps)->mergeplans[0];
else if (IsA(ps, ModifyTableState))
dpns->outer_planstate = ((ModifyTableState *) ps)->mt_plans[0];
else
dpns->outer_planstate = outerPlanState(ps);
if (dpns->outer_planstate)
dpns->outer_tlist = dpns->outer_planstate->plan->targetlist;
else
dpns->outer_tlist = NIL;
/*
* For a SubqueryScan, pretend the subplan is INNER referent. (We don't
* use OUTER because that could someday conflict with the normal meaning.)
* Likewise, for a CteScan, pretend the subquery's plan is INNER referent.
* For ON CONFLICT .. UPDATE we just need the inner tlist to point to the
* excluded expression's tlist. (Similar to the SubqueryScan we don't want
* to reuse OUTER, it's used for RETURNING in some modify table cases,
* although not INSERT .. CONFLICT).
*/
if (IsA(ps, SubqueryScanState))
dpns->inner_planstate = ((SubqueryScanState *) ps)->subplan;
else if (IsA(ps, CteScanState))
dpns->inner_planstate = ((CteScanState *) ps)->cteplanstate;
else if (IsA(ps, ModifyTableState))
dpns->inner_planstate = ps;
else
dpns->inner_planstate = innerPlanState(ps);
if (IsA(ps, ModifyTableState))
dpns->inner_tlist = ((ModifyTableState *) ps)->mt_excludedtlist;
else if (dpns->inner_planstate)
dpns->inner_tlist = dpns->inner_planstate->plan->targetlist;
else
dpns->inner_tlist = NIL;
/* Set up referent for INDEX_VAR Vars, if needed */
if (IsA(ps->plan, IndexOnlyScan))
dpns->index_tlist = ((IndexOnlyScan *) ps->plan)->indextlist;
else if (IsA(ps->plan, ForeignScan))
dpns->index_tlist = ((ForeignScan *) ps->plan)->fdw_scan_tlist;
else if (IsA(ps->plan, CustomScan))
dpns->index_tlist = ((CustomScan *) ps->plan)->custom_scan_tlist;
else
dpns->index_tlist = NIL;
}
/*
* push_child_plan: temporarily transfer deparsing attention to a child plan
*
* When expanding an OUTER_VAR or INNER_VAR reference, we must adjust the
* deparse context in case the referenced expression itself uses
* OUTER_VAR/INNER_VAR. We modify the top stack entry in-place to avoid
* affecting levelsup issues (although in a Plan tree there really shouldn't
* be any).
*
* Caller must provide a local deparse_namespace variable to save the
* previous state for pop_child_plan.
*/
static void
push_child_plan(deparse_namespace *dpns, PlanState *ps,
deparse_namespace *save_dpns)
{
/* Save state for restoration later */
*save_dpns = *dpns;
/* Link current plan node into ancestors list */
dpns->ancestors = lcons(dpns->planstate, dpns->ancestors);
/* Set attention on selected child */
set_deparse_planstate(dpns, ps);
}
/*
* pop_child_plan: undo the effects of push_child_plan
*/
static void
pop_child_plan(deparse_namespace *dpns, deparse_namespace *save_dpns)
{
List *ancestors;
/* Get rid of ancestors list cell added by push_child_plan */
ancestors = list_delete_first(dpns->ancestors);
/* Restore fields changed by push_child_plan */
*dpns = *save_dpns;
/* Make sure dpns->ancestors is right (may be unnecessary) */
dpns->ancestors = ancestors;
}
/*
* push_ancestor_plan: temporarily transfer deparsing attention to an
* ancestor plan
*
* When expanding a Param reference, we must adjust the deparse context
* to match the plan node that contains the expression being printed;
* otherwise we'd fail if that expression itself contains a Param or
* OUTER_VAR/INNER_VAR/INDEX_VAR variable.
*
* The target ancestor is conveniently identified by the ListCell holding it
* in dpns->ancestors.
*
* Caller must provide a local deparse_namespace variable to save the
* previous state for pop_ancestor_plan.
*/
static void
push_ancestor_plan(deparse_namespace *dpns, ListCell *ancestor_cell,
deparse_namespace *save_dpns)
{
PlanState *ps = (PlanState *) lfirst(ancestor_cell);
List *ancestors;
/* Save state for restoration later */
*save_dpns = *dpns;
/* Build a new ancestor list with just this node's ancestors */
ancestors = NIL;
while ((ancestor_cell = lnext(ancestor_cell)) != NULL)
ancestors = lappend(ancestors, lfirst(ancestor_cell));
dpns->ancestors = ancestors;
/* Set attention on selected ancestor */
set_deparse_planstate(dpns, ps);
}
/*
* pop_ancestor_plan: undo the effects of push_ancestor_plan
*/
static void
pop_ancestor_plan(deparse_namespace *dpns, deparse_namespace *save_dpns)
{
/* Free the ancestor list made in push_ancestor_plan */
list_free(dpns->ancestors);
/* Restore fields changed by push_ancestor_plan */
*dpns = *save_dpns;
}
/* ----------
* make_ruledef - reconstruct the CREATE RULE command
* for a given pg_rewrite tuple
* ----------
*/
static void
make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags)
{
char *rulename;
char ev_type;
Oid ev_class;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL;
int fno;
Datum dat;
bool isnull;
/*
* Get the attribute values from the rules tuple
*/
fno = SPI_fnumber(rulettc, "rulename");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
rulename = NameStr(*(DatumGetName(dat)));
fno = SPI_fnumber(rulettc, "ev_type");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_type = DatumGetChar(dat);
fno = SPI_fnumber(rulettc, "ev_class");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_class = DatumGetObjectId(dat);
fno = SPI_fnumber(rulettc, "is_instead");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
is_instead = DatumGetBool(dat);
/* these could be nulls */
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
/*
* Build the rules definition text
*/
appendStringInfo(buf, "CREATE RULE %s AS",
quote_identifier(rulename));
if (prettyFlags & PRETTYFLAG_INDENT)
appendStringInfoString(buf, "\n ON ");
else
appendStringInfoString(buf, " ON ");
/* The event the rule is fired for */
switch (ev_type)
{
case '1':
appendStringInfoString(buf, "SELECT");
break;
case '2':
appendStringInfoString(buf, "UPDATE");
break;
case '3':
appendStringInfoString(buf, "INSERT");
break;
case '4':
appendStringInfoString(buf, "DELETE");
break;
default:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule \"%s\" has unsupported event type %d",
rulename, ev_type)));
break;
}
/* The relation the rule is fired on */
appendStringInfo(buf, " TO %s", generate_relation_name(ev_class, NIL));
/* If the rule has an event qualification, add it */
if (ev_qual == NULL)
ev_qual = "";
if (strlen(ev_qual) > 0 && strcmp(ev_qual, "<>") != 0)
{
Node *qual;
Query *query;
deparse_context context;
deparse_namespace dpns;
if (prettyFlags & PRETTYFLAG_INDENT)
appendStringInfoString(buf, "\n ");
appendStringInfoString(buf, " WHERE ");
qual = stringToNode(ev_qual);
/*
* We need to make a context for recognizing any Vars in the qual
* (which can only be references to OLD and NEW). Use the rtable of
* the first query in the action list for this purpose.
*/
query = (Query *) linitial(actions);
/*
* If the action is INSERT...SELECT, OLD/NEW have been pushed down
* into the SELECT, and that's what we need to look at. (Ugly kluge
* ... try to fix this when we redesign querytrees.)
*/
query = getInsertSelectQuery(query, NULL);
/* Must acquire locks right away; see notes in get_query_def() */
AcquireRewriteLocks(query, false, false);
context.buf = buf;
context.namespaces = list_make1(&dpns);
context.windowClause = NIL;
context.windowTList = NIL;
context.varprefix = (list_length(query->rtable) != 1);
context.prettyFlags = prettyFlags;
context.wrapColumn = WRAP_COLUMN_DEFAULT;
context.indentLevel = PRETTYINDENT_STD;
context.special_exprkind = EXPR_KIND_NONE;
set_deparse_for_query(&dpns, query, NIL);
get_rule_expr(qual, &context, false);
}
appendStringInfoString(buf, " DO ");
/* The INSTEAD keyword (if so) */
if (is_instead)
appendStringInfoString(buf, "INSTEAD ");
/* Finally the rules actions */
if (list_length(actions) > 1)
{
ListCell *action;
Query *query;
appendStringInfoChar(buf, '(');
foreach(action, actions)
{
query = (Query *) lfirst(action);
get_query_def(query, buf, NIL, NULL,
prettyFlags, WRAP_COLUMN_DEFAULT, 0);
if (prettyFlags)
appendStringInfoString(buf, ";\n");
else
appendStringInfoString(buf, "; ");
}
appendStringInfoString(buf, ");");
}
else if (list_length(actions) == 0)
{
appendStringInfoString(buf, "NOTHING;");
}
else
{
Query *query;
query = (Query *) linitial(actions);
get_query_def(query, buf, NIL, NULL,
prettyFlags, WRAP_COLUMN_DEFAULT, 0);
appendStringInfoChar(buf, ';');
}
}
/* ----------
* make_viewdef - reconstruct the SELECT part of a
* view rewrite rule
* ----------
*/
static void
make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags, int wrapColumn)
{
Query *query;
char ev_type;
Oid ev_class;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL;
Relation ev_relation;
int fno;
bool isnull;
/*
* Get the attribute values from the rules tuple
*/
fno = SPI_fnumber(rulettc, "ev_type");
ev_type = (char) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_class");
ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "is_instead");
is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
if (list_length(actions) != 1)
{
appendStringInfoString(buf, "Not a view");
return;
}
query = (Query *) linitial(actions);
if (ev_type != '1' || !is_instead ||
strcmp(ev_qual, "<>") != 0 || query->commandType != CMD_SELECT)
{
appendStringInfoString(buf, "Not a view");
return;
}
ev_relation = heap_open(ev_class, AccessShareLock);
get_query_def(query, buf, NIL, RelationGetDescr(ev_relation),
prettyFlags, wrapColumn, 0);
appendStringInfoChar(buf, ';');
heap_close(ev_relation, AccessShareLock);
}
/* ----------
* get_query_def - Parse back one query parsetree
*
* If resultDesc is not NULL, then it is the output tuple descriptor for
* the view represented by a SELECT query.
* ----------
*/
static void
get_query_def(Query *query, StringInfo buf, List *parentnamespace,
TupleDesc resultDesc,
int prettyFlags, int wrapColumn, int startIndent)
{
deparse_context context;
deparse_namespace dpns;
/* Guard against excessively long or deeply-nested queries */
CHECK_FOR_INTERRUPTS();
check_stack_depth();
/*
* Before we begin to examine the query, acquire locks on referenced
* relations, and fix up deleted columns in JOIN RTEs. This ensures
* consistent results. Note we assume it's OK to scribble on the passed
* querytree!
*
* We are only deparsing the query (we are not about to execute it), so we
* only need AccessShareLock on the relations it mentions.
*/
AcquireRewriteLocks(query, false, false);
context.buf = buf;
context.namespaces = lcons(&dpns, list_copy(parentnamespace));
context.windowClause = NIL;
context.windowTList = NIL;
context.varprefix = (parentnamespace != NIL ||
list_length(query->rtable) != 1);
context.prettyFlags = prettyFlags;
context.wrapColumn = wrapColumn;
context.indentLevel = startIndent;
context.special_exprkind = EXPR_KIND_NONE;
set_deparse_for_query(&dpns, query, parentnamespace);
switch (query->commandType)
{
case CMD_SELECT:
get_select_query_def(query, &context, resultDesc);
break;
case CMD_UPDATE:
get_update_query_def(query, &context);
break;
case CMD_INSERT:
get_insert_query_def(query, &context);
break;
case CMD_DELETE:
get_delete_query_def(query, &context);
break;
case CMD_NOTHING:
appendStringInfoString(buf, "NOTHING");
break;
case CMD_UTILITY:
get_utility_query_def(query, &context);
break;
default:
elog(ERROR, "unrecognized query command type: %d",
query->commandType);
break;
}
}
/* ----------
* get_values_def - Parse back a VALUES list
* ----------
*/
static void
get_values_def(List *values_lists, deparse_context *context)
{
StringInfo buf = context->buf;
bool first_list = true;
ListCell *vtl;
appendStringInfoString(buf, "VALUES ");
foreach(vtl, values_lists)
{
List *sublist = (List *) lfirst(vtl);
bool first_col = true;
ListCell *lc;
if (first_list)
first_list = false;
else
appendStringInfoString(buf, ", ");
appendStringInfoChar(buf, '(');
foreach(lc, sublist)
{
Node *col = (Node *) lfirst(lc);
if (first_col)
first_col = false;
else
appendStringInfoChar(buf, ',');
/*
* Strip any top-level nodes representing indirection assignments,
* then print the result. Whole-row Vars need special treatment.
*/
get_rule_expr_toplevel(processIndirection(col, context, false),
context, false);
}
appendStringInfoChar(buf, ')');
}
}
/* ----------
* get_with_clause - Parse back a WITH clause
* ----------
*/
static void
get_with_clause(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
const char *sep;
ListCell *l;
if (query->cteList == NIL)
return;
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
if (query->hasRecursive)
sep = "WITH RECURSIVE ";
else
sep = "WITH ";
foreach(l, query->cteList)
{
CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
appendStringInfoString(buf, sep);
appendStringInfoString(buf, quote_identifier(cte->ctename));
if (cte->aliascolnames)
{
bool first = true;
ListCell *col;
appendStringInfoChar(buf, '(');
foreach(col, cte->aliascolnames)
{
if (first)
first = false;
else
appendStringInfoString(buf, ", ");
appendStringInfoString(buf,
quote_identifier(strVal(lfirst(col))));
}
appendStringInfoChar(buf, ')');
}
appendStringInfoString(buf, " AS (");
if (PRETTY_INDENT(context))
appendContextKeyword(context, "", 0, 0, 0);
get_query_def((Query *) cte->ctequery, buf, context->namespaces, NULL,
context->prettyFlags, context->wrapColumn,
context->indentLevel);
if (PRETTY_INDENT(context))
appendContextKeyword(context, "", 0, 0, 0);
appendStringInfoChar(buf, ')');
sep = ", ";
}
if (PRETTY_INDENT(context))
{
context->indentLevel -= PRETTYINDENT_STD;
appendContextKeyword(context, "", 0, 0, 0);
}
else
appendStringInfoChar(buf, ' ');
}
/* ----------
* get_select_query_def - Parse back a SELECT parsetree
* ----------
*/
static void
get_select_query_def(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
List *save_windowclause;
List *save_windowtlist;
bool force_colno;
ListCell *l;
/* Insert the WITH clause if given */
get_with_clause(query, context);
/* Set up context for possible window functions */
save_windowclause = context->windowClause;
context->windowClause = query->windowClause;
save_windowtlist = context->windowTList;
context->windowTList = query->targetList;
/*
* If the Query node has a setOperations tree, then it's the top level of
* a UNION/INTERSECT/EXCEPT query; only the WITH, ORDER BY and LIMIT
* fields are interesting in the top query itself.
*/
if (query->setOperations)
{
get_setop_query(query->setOperations, query, context, resultDesc);
/* ORDER BY clauses must be simple in this case */
force_colno = true;
}
else
{
get_basic_select_query(query, context, resultDesc);
force_colno = false;
}
/* Add the ORDER BY clause if given */
if (query->sortClause != NIL)
{
appendContextKeyword(context, " ORDER BY ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_orderby(query->sortClause, query->targetList,
force_colno, context);
}
/* Add the LIMIT clause if given */
if (query->limitOffset != NULL)
{
appendContextKeyword(context, " OFFSET ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
get_rule_expr(query->limitOffset, context, false);
}
if (query->limitCount != NULL)
{
appendContextKeyword(context, " LIMIT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
if (IsA(query->limitCount, Const) &&
((Const *) query->limitCount)->constisnull)
appendStringInfoString(buf, "ALL");
else
get_rule_expr(query->limitCount, context, false);
}
/* Add FOR [KEY] UPDATE/SHARE clauses if present */
if (query->hasForUpdate)
{
foreach(l, query->rowMarks)
{
RowMarkClause *rc = (RowMarkClause *) lfirst(l);
/* don't print implicit clauses */
if (rc->pushedDown)
continue;
switch (rc->strength)
{
case LCS_NONE:
/* we intentionally throw an error for LCS_NONE */
elog(ERROR, "unrecognized LockClauseStrength %d",
(int) rc->strength);
break;
case LCS_FORKEYSHARE:
appendContextKeyword(context, " FOR KEY SHARE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case LCS_FORSHARE:
appendContextKeyword(context, " FOR SHARE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case LCS_FORNOKEYUPDATE:
appendContextKeyword(context, " FOR NO KEY UPDATE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case LCS_FORUPDATE:
appendContextKeyword(context, " FOR UPDATE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
}
appendStringInfo(buf, " OF %s",
quote_identifier(get_rtable_name(rc->rti,
context)));
if (rc->waitPolicy == LockWaitError)
appendStringInfoString(buf, " NOWAIT");
else if (rc->waitPolicy == LockWaitSkip)
appendStringInfoString(buf, " SKIP LOCKED");
}
}
context->windowClause = save_windowclause;
context->windowTList = save_windowtlist;
}
/*
* Detect whether query looks like SELECT ... FROM VALUES();
* if so, return the VALUES RTE. Otherwise return NULL.
*/
static RangeTblEntry *
get_simple_values_rte(Query *query)
{
RangeTblEntry *result = NULL;
ListCell *lc;
/*
* We want to return TRUE even if the Query also contains OLD or NEW rule
* RTEs. So the idea is to scan the rtable and see if there is only one
* inFromCl RTE that is a VALUES RTE.
*/
foreach(lc, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
if (rte->rtekind == RTE_VALUES && rte->inFromCl)
{
if (result)
return NULL; /* multiple VALUES (probably not possible) */
result = rte;
}
else if (rte->rtekind == RTE_RELATION && !rte->inFromCl)
continue; /* ignore rule entries */
else
return NULL; /* something else -> not simple VALUES */
}
/*
* We don't need to check the targetlist in any great detail, because
* parser/analyze.c will never generate a "bare" VALUES RTE --- they only
* appear inside auto-generated sub-queries with very restricted
* structure. However, DefineView might have modified the tlist by
* injecting new column aliases; so compare tlist resnames against the
* RTE's names to detect that.
*/
if (result)
{
ListCell *lcn;
if (list_length(query->targetList) != list_length(result->eref->colnames))
return NULL; /* this probably cannot happen */
forboth(lc, query->targetList, lcn, result->eref->colnames)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
char *cname = strVal(lfirst(lcn));
if (tle->resjunk)
return NULL; /* this probably cannot happen */
if (tle->resname == NULL || strcmp(tle->resname, cname) != 0)
return NULL; /* column name has been changed */
}
}
return result;
}
static void
get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
RangeTblEntry *values_rte;
char *sep;
ListCell *l;
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
/*
* If the query looks like SELECT * FROM (VALUES ...), then print just the
* VALUES part. This reverses what transformValuesClause() did at parse
* time.
*/
values_rte = get_simple_values_rte(query);
if (values_rte)
{
get_values_def(values_rte->values_lists, context);
return;
}
/*
* Build up the query string - first we say SELECT
*/
appendStringInfoString(buf, "SELECT");
/* Add the DISTINCT clause if given */
if (query->distinctClause != NIL)
{
if (query->hasDistinctOn)
{
appendStringInfoString(buf, " DISTINCT ON (");
sep = "";
foreach(l, query->distinctClause)
{
SortGroupClause *srt = (SortGroupClause *) lfirst(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(srt->tleSortGroupRef, query->targetList,
false, context);
sep = ", ";
}
appendStringInfoChar(buf, ')');
}
else
appendStringInfoString(buf, " DISTINCT");
}
/* Then we tell what to select (the targetlist) */
get_target_list(query->targetList, context, resultDesc);
/* Add the FROM clause if needed */
get_from_clause(query, " FROM ", context);
/* Add the WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
/* Add the GROUP BY clause if given */
if (query->groupClause != NULL || query->groupingSets != NULL)
{
ParseExprKind save_exprkind;
appendContextKeyword(context, " GROUP BY ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
save_exprkind = context->special_exprkind;
context->special_exprkind = EXPR_KIND_GROUP_BY;
if (query->groupingSets == NIL)
{
sep = "";
foreach(l, query->groupClause)
{
SortGroupClause *grp = (SortGroupClause *) lfirst(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(grp->tleSortGroupRef, query->targetList,
false, context);
sep = ", ";
}
}
else
{
sep = "";
foreach(l, query->groupingSets)
{
GroupingSet *grp = lfirst(l);
appendStringInfoString(buf, sep);
get_rule_groupingset(grp, query->targetList, true, context);
sep = ", ";
}
}
context->special_exprkind = save_exprkind;
}
/* Add the HAVING clause if given */
if (query->havingQual != NULL)
{
appendContextKeyword(context, " HAVING ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
get_rule_expr(query->havingQual, context, false);
}
/* Add the WINDOW clause if needed */
if (query->windowClause != NIL)
get_rule_windowclause(query, context);
}
/* ----------
* get_target_list - Parse back a SELECT target list
*
* This is also used for RETURNING lists in INSERT/UPDATE/DELETE.
* ----------
*/
static void
get_target_list(List *targetList, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
StringInfoData targetbuf;
bool last_was_multiline = false;
char *sep;
int colno;
ListCell *l;
/* we use targetbuf to hold each TLE's text temporarily */
initStringInfo(&targetbuf);
sep = " ";
colno = 0;
foreach(l, targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
char *colname;
char *attname;
if (tle->resjunk)
continue; /* ignore junk entries */
appendStringInfoString(buf, sep);
sep = ", ";
colno++;
/*
* Put the new field text into targetbuf so we can decide after we've
* got it whether or not it needs to go on a new line.
*/
resetStringInfo(&targetbuf);
context->buf = &targetbuf;
/*
* We special-case Var nodes rather than using get_rule_expr. This is
* needed because get_rule_expr will display a whole-row Var as
* "foo.*", which is the preferred notation in most contexts, but at
* the top level of a SELECT list it's not right (the parser will
* expand that notation into multiple columns, yielding behavior
* different from a whole-row Var). We need to call get_variable
* directly so that we can tell it to do the right thing, and so that
* we can get the attribute name which is the default AS label.
*/
if (tle->expr && (IsA(tle->expr, Var)))
{
attname = get_variable((Var *) tle->expr, 0, true, context);
}
else
{
get_rule_expr((Node *) tle->expr, context, true);
/* We'll show the AS name unless it's this: */
attname = "?column?";
}
/*
* Figure out what the result column should be called. In the context
* of a view, use the view's tuple descriptor (so as to pick up the
* effects of any column RENAME that's been done on the view).
* Otherwise, just use what we can find in the TLE.
*/
if (resultDesc && colno <= resultDesc->natts)
colname = NameStr(resultDesc->attrs[colno - 1]->attname);
else
colname = tle->resname;
/* Show AS unless the column's name is correct as-is */
if (colname) /* resname could be NULL */
{
if (attname == NULL || strcmp(attname, colname) != 0)
appendStringInfo(&targetbuf, " AS %s", quote_identifier(colname));
}
/* Restore context's output buffer */
context->buf = buf;
/* Consider line-wrapping if enabled */
if (PRETTY_INDENT(context) && context->wrapColumn >= 0)
{
int leading_nl_pos;
/* Does the new field start with a new line? */
if (targetbuf.len > 0 && targetbuf.data[0] == '\n')
leading_nl_pos = 0;
else
leading_nl_pos = -1;
/* If so, we shouldn't add anything */
if (leading_nl_pos >= 0)
{
/* instead, remove any trailing spaces currently in buf */
removeStringInfoSpaces(buf);
}
else
{
char *trailing_nl;
/* Locate the start of the current line in the output buffer */
trailing_nl = strrchr(buf->data, '\n');
if (trailing_nl == NULL)
trailing_nl = buf->data;
else
trailing_nl++;
/*
* Add a newline, plus some indentation, if the new field is
* not the first and either the new field would cause an
* overflow or the last field used more than one line.
*/
if (colno > 1 &&
((strlen(trailing_nl) + targetbuf.len > context->wrapColumn) ||
last_was_multiline))
appendContextKeyword(context, "", -PRETTYINDENT_STD,
PRETTYINDENT_STD, PRETTYINDENT_VAR);
}
/* Remember this field's multiline status for next iteration */
last_was_multiline =
(strchr(targetbuf.data + leading_nl_pos + 1, '\n') != NULL);
}
/* Add the new field */
appendStringInfoString(buf, targetbuf.data);
}
/* clean up */
pfree(targetbuf.data);
}
static void
get_setop_query(Node *setOp, Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
bool need_paren;
/* Guard against excessively long or deeply-nested queries */
CHECK_FOR_INTERRUPTS();
check_stack_depth();
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable);
Query *subquery = rte->subquery;
Assert(subquery != NULL);
Assert(subquery->setOperations == NULL);
/* Need parens if WITH, ORDER BY, FOR UPDATE, or LIMIT; see gram.y */
need_paren = (subquery->cteList ||
subquery->sortClause ||
subquery->rowMarks ||
subquery->limitOffset ||
subquery->limitCount);
if (need_paren)
appendStringInfoChar(buf, '(');
get_query_def(subquery, buf, context->namespaces, resultDesc,
context->prettyFlags, context->wrapColumn,
context->indentLevel);
if (need_paren)
appendStringInfoChar(buf, ')');
}
else if (IsA(setOp, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) setOp;
int subindent;
/*
* We force parens when nesting two SetOperationStmts, except when the
* lefthand input is another setop of the same kind. Syntactically,
* we could omit parens in rather more cases, but it seems best to use
* parens to flag cases where the setop operator changes. If we use
* parens, we also increase the indentation level for the child query.
*
* There are some cases in which parens are needed around a leaf query
* too, but those are more easily handled at the next level down (see
* code above).
*/
if (IsA(op->larg, SetOperationStmt))
{
SetOperationStmt *lop = (SetOperationStmt *) op->larg;
if (op->op == lop->op && op->all == lop->all)
need_paren = false;
else
need_paren = true;
}
else
need_paren = false;
if (need_paren)
{
appendStringInfoChar(buf, '(');
subindent = PRETTYINDENT_STD;
appendContextKeyword(context, "", subindent, 0, 0);
}
else
subindent = 0;
get_setop_query(op->larg, query, context, resultDesc);
if (need_paren)
appendContextKeyword(context, ") ", -subindent, 0, 0);
else if (PRETTY_INDENT(context))
appendContextKeyword(context, "", -subindent, 0, 0);
else
appendStringInfoChar(buf, ' ');
switch (op->op)
{
case SETOP_UNION:
appendStringInfoString(buf, "UNION ");
break;
case SETOP_INTERSECT:
appendStringInfoString(buf, "INTERSECT ");
break;
case SETOP_EXCEPT:
appendStringInfoString(buf, "EXCEPT ");
break;
default:
elog(ERROR, "unrecognized set op: %d",
(int) op->op);
}
if (op->all)
appendStringInfoString(buf, "ALL ");
/* Always parenthesize if RHS is another setop */
need_paren = IsA(op->rarg, SetOperationStmt);
/*
* The indentation code here is deliberately a bit different from that
* for the lefthand input, because we want the line breaks in
* different places.
*/
if (need_paren)
{
appendStringInfoChar(buf, '(');
subindent = PRETTYINDENT_STD;
}
else
subindent = 0;
appendContextKeyword(context, "", subindent, 0, 0);
get_setop_query(op->rarg, query, context, resultDesc);
if (PRETTY_INDENT(context))
context->indentLevel -= subindent;
if (need_paren)
appendContextKeyword(context, ")", 0, 0, 0);
}
else
{
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(setOp));
}
}
/*
* Display a sort/group clause.
*
* Also returns the expression tree, so caller need not find it again.
*/
static Node *
get_rule_sortgroupclause(Index ref, List *tlist, bool force_colno,
deparse_context *context)
{
StringInfo buf = context->buf;
TargetEntry *tle;
Node *expr;
tle = get_sortgroupref_tle(ref, tlist);
expr = (Node *) tle->expr;
/*
* Use column-number form if requested by caller. Otherwise, if
* expression is a constant, force it to be dumped with an explicit cast
* as decoration --- this is because a simple integer constant is
* ambiguous (and will be misinterpreted by findTargetlistEntry()) if we
* dump it without any decoration. If it's anything more complex than a
* simple Var, then force extra parens around it, to ensure it can't be
* misinterpreted as a cube() or rollup() construct.
*/
if (force_colno)
{
Assert(!tle->resjunk);
appendStringInfo(buf, "%d", tle->resno);
}
else if (expr && IsA(expr, Const))
get_const_expr((Const *) expr, context, 1);
else if (!expr || IsA(expr, Var))
get_rule_expr(expr, context, true);
else
{
/*
* We must force parens for function-like expressions even if
* PRETTY_PAREN is off, since those are the ones in danger of
* misparsing. For other expressions we need to force them only if
* PRETTY_PAREN is on, since otherwise the expression will output them
* itself. (We can't skip the parens.)
*/
bool need_paren = (PRETTY_PAREN(context)
|| IsA(expr, FuncExpr)
||IsA(expr, Aggref)
||IsA(expr, WindowFunc));
if (need_paren)
appendStringInfoString(context->buf, "(");
get_rule_expr(expr, context, true);
if (need_paren)
appendStringInfoString(context->buf, ")");
}
return expr;
}
/*
* Display a GroupingSet
*/
static void
get_rule_groupingset(GroupingSet *gset, List *targetlist,
bool omit_parens, deparse_context *context)
{
ListCell *l;
StringInfo buf = context->buf;
bool omit_child_parens = true;
char *sep = "";
switch (gset->kind)
{
case GROUPING_SET_EMPTY:
appendStringInfoString(buf, "()");
return;
case GROUPING_SET_SIMPLE:
{
if (!omit_parens || list_length(gset->content) != 1)
appendStringInfoString(buf, "(");
foreach(l, gset->content)
{
Index ref = lfirst_int(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(ref, targetlist,
false, context);
sep = ", ";
}
if (!omit_parens || list_length(gset->content) != 1)
appendStringInfoString(buf, ")");
}
return;
case GROUPING_SET_ROLLUP:
appendStringInfoString(buf, "ROLLUP(");
break;
case GROUPING_SET_CUBE:
appendStringInfoString(buf, "CUBE(");
break;
case GROUPING_SET_SETS:
appendStringInfoString(buf, "GROUPING SETS (");
omit_child_parens = false;
break;
}
foreach(l, gset->content)
{
appendStringInfoString(buf, sep);
get_rule_groupingset(lfirst(l), targetlist, omit_child_parens, context);
sep = ", ";
}
appendStringInfoString(buf, ")");
}
/*
* Display an ORDER BY list.
*/
static void
get_rule_orderby(List *orderList, List *targetList,
bool force_colno, deparse_context *context)
{
StringInfo buf = context->buf;
const char *sep;
ListCell *l;
sep = "";
foreach(l, orderList)
{
SortGroupClause *srt = (SortGroupClause *) lfirst(l);
Node *sortexpr;
Oid sortcoltype;
TypeCacheEntry *typentry;
appendStringInfoString(buf, sep);
sortexpr = get_rule_sortgroupclause(srt->tleSortGroupRef, targetList,
force_colno, context);
sortcoltype = exprType(sortexpr);
/* See whether operator is default < or > for datatype */
typentry = lookup_type_cache(sortcoltype,
TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
if (srt->sortop == typentry->lt_opr)
{
/* ASC is default, so emit nothing for it */
if (srt->nulls_first)
appendStringInfoString(buf, " NULLS FIRST");
}
else if (srt->sortop == typentry->gt_opr)
{
appendStringInfoString(buf, " DESC");
/* DESC defaults to NULLS FIRST */
if (!srt->nulls_first)
appendStringInfoString(buf, " NULLS LAST");
}
else
{
appendStringInfo(buf, " USING %s",
generate_operator_name(srt->sortop,
sortcoltype,
sortcoltype));
/* be specific to eliminate ambiguity */
if (srt->nulls_first)
appendStringInfoString(buf, " NULLS FIRST");
else
appendStringInfoString(buf, " NULLS LAST");
}
sep = ", ";
}
}
/*
* Display a WINDOW clause.
*
* Note that the windowClause list might contain only anonymous window
* specifications, in which case we should print nothing here.
*/
static void
get_rule_windowclause(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
const char *sep;
ListCell *l;
sep = NULL;
foreach(l, query->windowClause)
{
WindowClause *wc = (WindowClause *) lfirst(l);
if (wc->name == NULL)
continue; /* ignore anonymous windows */
if (sep == NULL)
appendContextKeyword(context, " WINDOW ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
else
appendStringInfoString(buf, sep);
appendStringInfo(buf, "%s AS ", quote_identifier(wc->name));
get_rule_windowspec(wc, query->targetList, context);
sep = ", ";
}
}
/*
* Display a window definition
*/
static void
get_rule_windowspec(WindowClause *wc, List *targetList,
deparse_context *context)
{
StringInfo buf = context->buf;
bool needspace = false;
const char *sep;
ListCell *l;
appendStringInfoChar(buf, '(');
if (wc->refname)
{
appendStringInfoString(buf, quote_identifier(wc->refname));
needspace = true;
}
/* partition clauses are always inherited, so only print if no refname */
if (wc->partitionClause && !wc->refname)
{
if (needspace)
appendStringInfoChar(buf, ' ');
appendStringInfoString(buf, "PARTITION BY ");
sep = "";
foreach(l, wc->partitionClause)
{
SortGroupClause *grp = (SortGroupClause *) lfirst(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(grp->tleSortGroupRef, targetList,
false, context);
sep = ", ";
}
needspace = true;
}
/* print ordering clause only if not inherited */
if (wc->orderClause && !wc->copiedOrder)
{
if (needspace)
appendStringInfoChar(buf, ' ');
appendStringInfoString(buf, "ORDER BY ");
get_rule_orderby(wc->orderClause, targetList, false, context);
needspace = true;
}
/* framing clause is never inherited, so print unless it's default */
if (wc->frameOptions & FRAMEOPTION_NONDEFAULT)
{
if (needspace)
appendStringInfoChar(buf, ' ');
if (wc->frameOptions & FRAMEOPTION_RANGE)
appendStringInfoString(buf, "RANGE ");
else if (wc->frameOptions & FRAMEOPTION_ROWS)
appendStringInfoString(buf, "ROWS ");
else
Assert(false);
if (wc->frameOptions & FRAMEOPTION_BETWEEN)
appendStringInfoString(buf, "BETWEEN ");
if (wc->frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
appendStringInfoString(buf, "UNBOUNDED PRECEDING ");
else if (wc->frameOptions & FRAMEOPTION_START_CURRENT_ROW)
appendStringInfoString(buf, "CURRENT ROW ");
else if (wc->frameOptions & FRAMEOPTION_START_VALUE)
{
get_rule_expr(wc->startOffset, context, false);
if (wc->frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
appendStringInfoString(buf, " PRECEDING ");
else if (wc->frameOptions & FRAMEOPTION_START_VALUE_FOLLOWING)
appendStringInfoString(buf, " FOLLOWING ");
else
Assert(false);
}
else
Assert(false);
if (wc->frameOptions & FRAMEOPTION_BETWEEN)
{
appendStringInfoString(buf, "AND ");
if (wc->frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
appendStringInfoString(buf, "UNBOUNDED FOLLOWING ");
else if (wc->frameOptions & FRAMEOPTION_END_CURRENT_ROW)
appendStringInfoString(buf, "CURRENT ROW ");
else if (wc->frameOptions & FRAMEOPTION_END_VALUE)
{
get_rule_expr(wc->endOffset, context, false);
if (wc->frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
appendStringInfoString(buf, " PRECEDING ");
else if (wc->frameOptions & FRAMEOPTION_END_VALUE_FOLLOWING)
appendStringInfoString(buf, " FOLLOWING ");
else
Assert(false);
}
else
Assert(false);
}
/* we will now have a trailing space; remove it */
buf->len--;
}
appendStringInfoChar(buf, ')');
}
/* ----------
* get_insert_query_def - Parse back an INSERT parsetree
* ----------
*/
static void
get_insert_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *select_rte = NULL;
RangeTblEntry *values_rte = NULL;
RangeTblEntry *rte;
char *sep;
ListCell *values_cell;
ListCell *l;
List *strippedexprs;
/* Insert the WITH clause if given */
get_with_clause(query, context);
/*
* If it's an INSERT ... SELECT or multi-row VALUES, there will be a
* single RTE for the SELECT or VALUES. Plain VALUES has neither.
*/
foreach(l, query->rtable)
{
rte = (RangeTblEntry *) lfirst(l);
if (rte->rtekind == RTE_SUBQUERY)
{
if (select_rte)
elog(ERROR, "too many subquery RTEs in INSERT");
select_rte = rte;
}
if (rte->rtekind == RTE_VALUES)
{
if (values_rte)
elog(ERROR, "too many values RTEs in INSERT");
values_rte = rte;
}
}
if (select_rte && values_rte)
elog(ERROR, "both subquery and values RTEs in INSERT");
/*
* Start the query with INSERT INTO relname
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
appendStringInfo(buf, "INSERT INTO %s ",
generate_relation_name(rte->relid, NIL));
/* INSERT requires AS keyword for target alias */
if (rte->alias != NULL)
appendStringInfo(buf, "AS %s ",
quote_identifier(rte->alias->aliasname));
/*
* Add the insert-column-names list. To handle indirection properly, we
* need to look for indirection nodes in the top targetlist (if it's
* INSERT ... SELECT or INSERT ... single VALUES), or in the first
* expression list of the VALUES RTE (if it's INSERT ... multi VALUES). We
* assume that all the expression lists will have similar indirection in
* the latter case.
*/
if (values_rte)
values_cell = list_head((List *) linitial(values_rte->values_lists));
else
values_cell = NULL;
strippedexprs = NIL;
sep = "";
if (query->targetList)
appendStringInfoChar(buf, '(');
foreach(l, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->resjunk)
continue; /* ignore junk entries */
appendStringInfoString(buf, sep);
sep = ", ";
/*
* Put out name of target column; look in the catalogs, not at
* tle->resname, since resname will fail to track RENAME.
*/
appendStringInfoString(buf,
quote_identifier(get_relid_attribute_name(rte->relid,
tle->resno)));
/*
* Print any indirection needed (subfields or subscripts), and strip
* off the top-level nodes representing the indirection assignments.
*/
if (values_cell)
{
/* we discard the stripped expression in this case */
processIndirection((Node *) lfirst(values_cell), context, true);
values_cell = lnext(values_cell);
}
else
{
/* we keep a list of the stripped expressions in this case */
strippedexprs = lappend(strippedexprs,
processIndirection((Node *) tle->expr,
context, true));
}
}
if (query->targetList)
appendStringInfoString(buf, ") ");
if (select_rte)
{
/* Add the SELECT */
get_query_def(select_rte->subquery, buf, NIL, NULL,
context->prettyFlags, context->wrapColumn,
context->indentLevel);
}
else if (values_rte)
{
/* Add the multi-VALUES expression lists */
get_values_def(values_rte->values_lists, context);
}
else if (strippedexprs)
{
/* Add the single-VALUES expression list */
appendContextKeyword(context, "VALUES (",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
get_rule_expr((Node *) strippedexprs, context, false);
appendStringInfoChar(buf, ')');
}
else
{
/* No expressions, so it must be DEFAULT VALUES */
appendStringInfoString(buf, "DEFAULT VALUES");
}
/* Add ON CONFLICT if present */
if (query->onConflict)
{
OnConflictExpr *confl = query->onConflict;
appendStringInfoString(buf, " ON CONFLICT");
if (confl->arbiterElems)
{
/* Add the single-VALUES expression list */
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) confl->arbiterElems, context, false);
appendStringInfoChar(buf, ')');
/* Add a WHERE clause (for partial indexes) if given */
if (confl->arbiterWhere != NULL)
{
bool save_varprefix;
/*
* Force non-prefixing of Vars, since parser assumes that they
* belong to target relation. WHERE clause does not use
* InferenceElem, so this is separately required.
*/
save_varprefix = context->varprefix;
context->varprefix = false;
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(confl->arbiterWhere, context, false);
context->varprefix = save_varprefix;
}
}
else if (OidIsValid(confl->constraint))
{
char *constraint = get_constraint_name(confl->constraint);
if (!constraint)
elog(ERROR, "cache lookup failed for constraint %u",
confl->constraint);
appendStringInfo(buf, " ON CONSTRAINT %s",
quote_identifier(constraint));
}
if (confl->action == ONCONFLICT_NOTHING)
{
appendStringInfoString(buf, " DO NOTHING");
}
else
{
appendStringInfoString(buf, " DO UPDATE SET ");
/* Deparse targetlist */
get_update_query_targetlist_def(query, confl->onConflictSet,
context, rte);
/* Add a WHERE clause if given */
if (confl->onConflictWhere != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(confl->onConflictWhere, context, false);
}
}
}
/* Add RETURNING if present */
if (query->returningList)
{
appendContextKeyword(context, " RETURNING",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_target_list(query->returningList, context, NULL);
}
}
/* ----------
* get_update_query_def - Parse back an UPDATE parsetree
* ----------
*/
static void
get_update_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *rte;
/* Insert the WITH clause if given */
get_with_clause(query, context);
/*
* Start the query with UPDATE relname SET
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
appendStringInfoChar(buf, ' ');
context->indentLevel += PRETTYINDENT_STD;
}
appendStringInfo(buf, "UPDATE %s%s",
only_marker(rte),
generate_relation_name(rte->relid, NIL));
if (rte->alias != NULL)
appendStringInfo(buf, " %s",
quote_identifier(rte->alias->aliasname));
appendStringInfoString(buf, " SET ");
/* Deparse targetlist */
get_update_query_targetlist_def(query, query->targetList, context, rte);
/* Add the FROM clause if needed */
get_from_clause(query, " FROM ", context);
/* Add a WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
/* Add RETURNING if present */
if (query->returningList)
{
appendContextKeyword(context, " RETURNING",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_target_list(query->returningList, context, NULL);
}
}
/* ----------
* get_update_query_targetlist_def - Parse back an UPDATE targetlist
* ----------
*/
static void
get_update_query_targetlist_def(Query *query, List *targetList,
deparse_context *context, RangeTblEntry *rte)
{
StringInfo buf = context->buf;
ListCell *l;
ListCell *next_ma_cell;
int remaining_ma_columns;
const char *sep;
SubLink *cur_ma_sublink;
List *ma_sublinks;
/*
* Prepare to deal with MULTIEXPR assignments: collect the source SubLinks
* into a list. We expect them to appear, in ID order, in resjunk tlist
* entries.
*/
ma_sublinks = NIL;
if (query->hasSubLinks) /* else there can't be any */
{
foreach(l, targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->resjunk && IsA(tle->expr, SubLink))
{
SubLink *sl = (SubLink *) tle->expr;
if (sl->subLinkType == MULTIEXPR_SUBLINK)
{
ma_sublinks = lappend(ma_sublinks, sl);
Assert(sl->subLinkId == list_length(ma_sublinks));
}
}
}
}
next_ma_cell = list_head(ma_sublinks);
cur_ma_sublink = NULL;
remaining_ma_columns = 0;
/* Add the comma separated list of 'attname = value' */
sep = "";
foreach(l, targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *expr;
if (tle->resjunk)
continue; /* ignore junk entries */
/* Emit separator (OK whether we're in multiassignment or not) */
appendStringInfoString(buf, sep);
sep = ", ";
/*
* Check to see if we're starting a multiassignment group: if so,
* output a left paren.
*/
if (next_ma_cell != NULL && cur_ma_sublink == NULL)
{
/*
* We must dig down into the expr to see if it's a PARAM_MULTIEXPR
* Param. That could be buried under FieldStores and ArrayRefs
* (cf processIndirection()), and underneath those there could be
* an implicit type coercion.
*/
expr = (Node *) tle->expr;
while (expr)
{
if (IsA(expr, FieldStore))
{
FieldStore *fstore = (FieldStore *) expr;
expr = (Node *) linitial(fstore->newvals);
}
else if (IsA(expr, ArrayRef))
{
ArrayRef *aref = (ArrayRef *) expr;
if (aref->refassgnexpr == NULL)
break;
expr = (Node *) aref->refassgnexpr;
}
else
break;
}
expr = strip_implicit_coercions(expr);
if (expr && IsA(expr, Param) &&
((Param *) expr)->paramkind == PARAM_MULTIEXPR)
{
cur_ma_sublink = (SubLink *) lfirst(next_ma_cell);
next_ma_cell = lnext(next_ma_cell);
remaining_ma_columns = count_nonjunk_tlist_entries(
((Query *) cur_ma_sublink->subselect)->targetList);
Assert(((Param *) expr)->paramid ==
((cur_ma_sublink->subLinkId << 16) | 1));
appendStringInfoChar(buf, '(');
}
}
/*
* Put out name of target column; look in the catalogs, not at
* tle->resname, since resname will fail to track RENAME.
*/
appendStringInfoString(buf,
quote_identifier(get_relid_attribute_name(rte->relid,
tle->resno)));
/*
* Print any indirection needed (subfields or subscripts), and strip
* off the top-level nodes representing the indirection assignments.
*/
expr = processIndirection((Node *) tle->expr, context, true);
/*
* If we're in a multiassignment, skip printing anything more, unless
* this is the last column; in which case, what we print should be the
* sublink, not the Param.
*/
if (cur_ma_sublink != NULL)
{
if (--remaining_ma_columns > 0)
continue; /* not the last column of multiassignment */
appendStringInfoChar(buf, ')');
expr = (Node *) cur_ma_sublink;
cur_ma_sublink = NULL;
}
appendStringInfoString(buf, " = ");
get_rule_expr(expr, context, false);
}
}
/* ----------
* get_delete_query_def - Parse back a DELETE parsetree
* ----------
*/
static void
get_delete_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *rte;
/* Insert the WITH clause if given */
get_with_clause(query, context);
/*
* Start the query with DELETE FROM relname
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
appendStringInfoChar(buf, ' ');
context->indentLevel += PRETTYINDENT_STD;
}
appendStringInfo(buf, "DELETE FROM %s%s",
only_marker(rte),
generate_relation_name(rte->relid, NIL));
if (rte->alias != NULL)
appendStringInfo(buf, " %s",
quote_identifier(rte->alias->aliasname));
/* Add the USING clause if given */
get_from_clause(query, " USING ", context);
/* Add a WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
/* Add RETURNING if present */
if (query->returningList)
{
appendContextKeyword(context, " RETURNING",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_target_list(query->returningList, context, NULL);
}
}
/* ----------
* get_utility_query_def - Parse back a UTILITY parsetree
* ----------
*/
static void
get_utility_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
if (query->utilityStmt && IsA(query->utilityStmt, NotifyStmt))
{
NotifyStmt *stmt = (NotifyStmt *) query->utilityStmt;
appendContextKeyword(context, "",
0, PRETTYINDENT_STD, 1);
appendStringInfo(buf, "NOTIFY %s",
quote_identifier(stmt->conditionname));
if (stmt->payload)
{
appendStringInfoString(buf, ", ");
simple_quote_literal(buf, stmt->payload);
}
}
else
{
/* Currently only NOTIFY utility commands can appear in rules */
elog(ERROR, "unexpected utility statement type");
}
}
/*
* Display a Var appropriately.
*
* In some cases (currently only when recursing into an unnamed join)
* the Var's varlevelsup has to be interpreted with respect to a context
* above the current one; levelsup indicates the offset.
*
* If istoplevel is TRUE, the Var is at the top level of a SELECT's
* targetlist, which means we need special treatment of whole-row Vars.
* Instead of the normal "tab.*", we'll print "tab.*::typename", which is a
* dirty hack to prevent "tab.*" from being expanded into multiple columns.
* (The parser will strip the useless coercion, so no inefficiency is added in
* dump and reload.) We used to print just "tab" in such cases, but that is
* ambiguous and will yield the wrong result if "tab" is also a plain column
* name in the query.
*
* Returns the attname of the Var, or NULL if the Var has no attname (because
* it is a whole-row Var or a subplan output reference).
*/
static char *
get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *rte;
AttrNumber attnum;
int netlevelsup;
deparse_namespace *dpns;
deparse_columns *colinfo;
char *refname;
char *attname;
/* Find appropriate nesting depth */
netlevelsup = var->varlevelsup + levelsup;
if (netlevelsup >= list_length(context->namespaces))
elog(ERROR, "bogus varlevelsup: %d offset %d",
var->varlevelsup, levelsup);
dpns = (deparse_namespace *) list_nth(context->namespaces,
netlevelsup);
/*
* Try to find the relevant RTE in this rtable. In a plan tree, it's
* likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig
* down into the subplans, or INDEX_VAR, which is resolved similarly. Also
* find the aliases previously assigned for this RTE.
*/
if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
{
rte = rt_fetch(var->varno, dpns->rtable);
refname = (char *) list_nth(dpns->rtable_names, var->varno - 1);
colinfo = deparse_columns_fetch(var->varno, dpns);
attnum = var->varattno;
}
else
{
resolve_special_varno((Node *) var, context, NULL,
get_special_variable);
return NULL;
}
/*
* The planner will sometimes emit Vars referencing resjunk elements of a
* subquery's target list (this is currently only possible if it chooses
* to generate a "physical tlist" for a SubqueryScan or CteScan node).
* Although we prefer to print subquery-referencing Vars using the
* subquery's alias, that's not possible for resjunk items since they have
* no alias. So in that case, drill down to the subplan and print the
* contents of the referenced tlist item. This works because in a plan
* tree, such Vars can only occur in a SubqueryScan or CteScan node, and
* we'll have set dpns->inner_planstate to reference the child plan node.
*/
if ((rte->rtekind == RTE_SUBQUERY || rte->rtekind == RTE_CTE) &&
attnum > list_length(rte->eref->colnames) &&
dpns->inner_planstate)
{
TargetEntry *tle;
deparse_namespace save_dpns;
tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
elog(ERROR, "invalid attnum %d for relation \"%s\"",
var->varattno, rte->eref->aliasname);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
/*
* Force parentheses because our caller probably assumed a Var is a
* simple expression.
*/
if (!IsA(tle->expr, Var))
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) tle->expr, context, true);
if (!IsA(tle->expr, Var))
appendStringInfoChar(buf, ')');
pop_child_plan(dpns, &save_dpns);
return NULL;
}
/*
* If it's an unnamed join, look at the expansion of the alias variable.
* If it's a simple reference to one of the input vars, then recursively
* print the name of that var instead. When it's not a simple reference,
* we have to just print the unqualified join column name. (This can only
* happen with "dangerous" merged columns in a JOIN USING; we took pains
* previously to make the unqualified column name unique in such cases.)
*
* This wouldn't work in decompiling plan trees, because we don't store
* joinaliasvars lists after planning; but a plan tree should never
* contain a join alias variable.
*/
if (rte->rtekind == RTE_JOIN && rte->alias == NULL)
{
if (rte->joinaliasvars == NIL)
elog(ERROR, "cannot decompile join alias var in plan tree");
if (attnum > 0)
{
Var *aliasvar;
aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
/* we intentionally don't strip implicit coercions here */
if (aliasvar && IsA(aliasvar, Var))
{
return get_variable(aliasvar, var->varlevelsup + levelsup,
istoplevel, context);
}
}
/*
* Unnamed join has no refname. (Note: since it's unnamed, there is
* no way the user could have referenced it to create a whole-row Var
* for it. So we don't have to cover that case below.)
*/
Assert(refname == NULL);
}
if (attnum == InvalidAttrNumber)
attname = NULL;
else if (attnum > 0)
{
/* Get column name to use from the colinfo struct */
if (attnum > colinfo->num_cols)
elog(ERROR, "invalid attnum %d for relation \"%s\"",
attnum, rte->eref->aliasname);
attname = colinfo->colnames[attnum - 1];
if (attname == NULL) /* dropped column? */
elog(ERROR, "invalid attnum %d for relation \"%s\"",
attnum, rte->eref->aliasname);
}
else
{
/* System column - name is fixed, get it from the catalog */
attname = get_rte_attribute_name(rte, attnum);
}
if (refname && (context->varprefix || attname == NULL))
{
appendStringInfoString(buf, quote_identifier(refname));
appendStringInfoChar(buf, '.');
}
if (attname)
appendStringInfoString(buf, quote_identifier(attname));
else
{
appendStringInfoChar(buf, '*');
if (istoplevel)
appendStringInfo(buf, "::%s",
format_type_with_typemod(var->vartype,
var->vartypmod));
}
return attname;
}
/*
* Deparse a Var which references OUTER_VAR, INNER_VAR, or INDEX_VAR. This
* routine is actually a callback for get_special_varno, which handles finding
* the correct TargetEntry. We get the expression contained in that
* TargetEntry and just need to deparse it, a job we can throw back on
* get_rule_expr.
*/
static void
get_special_variable(Node *node, deparse_context *context, void *private)
{
StringInfo buf = context->buf;
/*
* Force parentheses because our caller probably assumed a Var is a simple
* expression.
*/
if (!IsA(node, Var))
appendStringInfoChar(buf, '(');
get_rule_expr(node, context, true);
if (!IsA(node, Var))
appendStringInfoChar(buf, ')');
}
/*
* Chase through plan references to special varnos (OUTER_VAR, INNER_VAR,
* INDEX_VAR) until we find a real Var or some kind of non-Var node; then,
* invoke the callback provided.
*/
static void
resolve_special_varno(Node *node, deparse_context *context, void *private,
void (*callback) (Node *, deparse_context *, void *))
{
Var *var;
deparse_namespace *dpns;
/* If it's not a Var, invoke the callback. */
if (!IsA(node, Var))
{
callback(node, context, private);
return;
}
/* Find appropriate nesting depth */
var = (Var *) node;
dpns = (deparse_namespace *) list_nth(context->namespaces,
var->varlevelsup);
/*
* It's a special RTE, so recurse.
*/
if (var->varno == OUTER_VAR && dpns->outer_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
tle = get_tle_by_resno(dpns->outer_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno);
push_child_plan(dpns, dpns->outer_planstate, &save_dpns);
resolve_special_varno((Node *) tle->expr, context, private, callback);
pop_child_plan(dpns, &save_dpns);
return;
}
else if (var->varno == INNER_VAR && dpns->inner_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
resolve_special_varno((Node *) tle->expr, context, private, callback);
pop_child_plan(dpns, &save_dpns);
return;
}
else if (var->varno == INDEX_VAR && dpns->index_tlist)
{
TargetEntry *tle;
tle = get_tle_by_resno(dpns->index_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno);
resolve_special_varno((Node *) tle->expr, context, private, callback);
return;
}
else if (var->varno < 1 || var->varno > list_length(dpns->rtable))
elog(ERROR, "bogus varno: %d", var->varno);
/* Not special. Just invoke the callback. */
callback(node, context, private);
}
/*
* Get the name of a field of an expression of composite type. The
* expression is usually a Var, but we handle other cases too.
*
* levelsup is an extra offset to interpret the Var's varlevelsup correctly.
*
* This is fairly straightforward when the expression has a named composite
* type; we need only look up the type in the catalogs. However, the type
* could also be RECORD. Since no actual table or view column is allowed to
* have type RECORD, a Var of type RECORD must refer to a JOIN or FUNCTION RTE
* or to a subquery output. We drill down to find the ultimate defining
* expression and attempt to infer the field name from it. We ereport if we
* can't determine the name.
*
* Similarly, a PARAM of type RECORD has to refer to some expression of
* a determinable composite type.
*/
static const char *
get_name_for_var_field(Var *var, int fieldno,
int levelsup, deparse_context *context)
{
RangeTblEntry *rte;
AttrNumber attnum;
int netlevelsup;
deparse_namespace *dpns;
TupleDesc tupleDesc;
Node *expr;
/*
* If it's a RowExpr that was expanded from a whole-row Var, use the
* column names attached to it.
*/
if (IsA(var, RowExpr))
{
RowExpr *r = (RowExpr *) var;
if (fieldno > 0 && fieldno <= list_length(r->colnames))
return strVal(list_nth(r->colnames, fieldno - 1));
}
/*
* If it's a Param of type RECORD, try to find what the Param refers to.
*/
if (IsA(var, Param))
{
Param *param = (Param *) var;
ListCell *ancestor_cell;
expr = find_param_referent(param, context, &dpns, &ancestor_cell);
if (expr)
{
/* Found a match, so recurse to decipher the field name */
deparse_namespace save_dpns;
const char *result;
push_ancestor_plan(dpns, ancestor_cell, &save_dpns);
result = get_name_for_var_field((Var *) expr, fieldno,
0, context);
pop_ancestor_plan(dpns, &save_dpns);
return result;
}
}
/*
* If it's a Var of type RECORD, we have to find what the Var refers to;
* if not, we can use get_expr_result_type. If that fails, we try
* lookup_rowtype_tupdesc, which will probably fail too, but will ereport
* an acceptable message.
*/
if (!IsA(var, Var) ||
var->vartype != RECORDOID)
{
if (get_expr_result_type((Node *) var, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
tupleDesc = lookup_rowtype_tupdesc_copy(exprType((Node *) var),
exprTypmod((Node *) var));
Assert(tupleDesc);
/* Got the tupdesc, so we can extract the field name */
Assert(fieldno >= 1 && fieldno <= tupleDesc->natts);
return NameStr(tupleDesc->attrs[fieldno - 1]->attname);
}
/* Find appropriate nesting depth */
netlevelsup = var->varlevelsup + levelsup;
if (netlevelsup >= list_length(context->namespaces))
elog(ERROR, "bogus varlevelsup: %d offset %d",
var->varlevelsup, levelsup);
dpns = (deparse_namespace *) list_nth(context->namespaces,
netlevelsup);
/*
* Try to find the relevant RTE in this rtable. In a plan tree, it's
* likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig
* down into the subplans, or INDEX_VAR, which is resolved similarly.
*/
if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
{
rte = rt_fetch(var->varno, dpns->rtable);
attnum = var->varattno;
}
else if (var->varno == OUTER_VAR && dpns->outer_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
tle = get_tle_by_resno(dpns->outer_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->outer_planstate, &save_dpns);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
pop_child_plan(dpns, &save_dpns);
return result;
}
else if (var->varno == INNER_VAR && dpns->inner_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
pop_child_plan(dpns, &save_dpns);
return result;
}
else if (var->varno == INDEX_VAR && dpns->index_tlist)
{
TargetEntry *tle;
const char *result;
tle = get_tle_by_resno(dpns->index_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
return result;
}
else
{
elog(ERROR, "bogus varno: %d", var->varno);
return NULL; /* keep compiler quiet */
}
if (attnum == InvalidAttrNumber)
{
/* Var is whole-row reference to RTE, so select the right field */
return get_rte_attribute_name(rte, fieldno);
}
/*
* This part has essentially the same logic as the parser's
* expandRecordVariable() function, but we are dealing with a different
* representation of the input context, and we only need one field name
* not a TupleDesc. Also, we need special cases for finding subquery and
* CTE subplans when deparsing Plan trees.
*/
expr = (Node *) var; /* default if we can't drill down */
switch (rte->rtekind)
{
case RTE_RELATION:
case RTE_VALUES:
/*
* This case should not occur: a column of a table or values list
* shouldn't have type RECORD. Fall through and fail (most
* likely) at the bottom.
*/
break;
case RTE_SUBQUERY:
/* Subselect-in-FROM: examine sub-select's output expr */
{
if (rte->subquery)
{
TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
expr = (Node *) ste->expr;
if (IsA(expr, Var))
{
/*
* Recurse into the sub-select to see what its Var
* refers to. We have to build an additional level of
* namespace to keep in step with varlevelsup in the
* subselect.
*/
deparse_namespace mydpns;
const char *result;
set_deparse_for_query(&mydpns, rte->subquery,
context->namespaces);
context->namespaces = lcons(&mydpns,
context->namespaces);
result = get_name_for_var_field((Var *) expr, fieldno,
0, context);
context->namespaces =
list_delete_first(context->namespaces);
return result;
}
/* else fall through to inspect the expression */
}
else
{
/*
* We're deparsing a Plan tree so we don't have complete
* RTE entries (in particular, rte->subquery is NULL). But
* the only place we'd see a Var directly referencing a
* SUBQUERY RTE is in a SubqueryScan plan node, and we can
* look into the child plan's tlist instead.
*/
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
if (!dpns->inner_planstate)
elog(ERROR, "failed to find plan for subquery %s",
rte->eref->aliasname);
tle = get_tle_by_resno(dpns->inner_tlist, attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
pop_child_plan(dpns, &save_dpns);
return result;
}
}
break;
case RTE_JOIN:
/* Join RTE --- recursively inspect the alias variable */
if (rte->joinaliasvars == NIL)
elog(ERROR, "cannot decompile join alias var in plan tree");
Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
Assert(expr != NULL);
/* we intentionally don't strip implicit coercions here */
if (IsA(expr, Var))
return get_name_for_var_field((Var *) expr, fieldno,
var->varlevelsup + levelsup,
context);
/* else fall through to inspect the expression */
break;
case RTE_FUNCTION:
/*
* We couldn't get here unless a function is declared with one of
* its result columns as RECORD, which is not allowed.
*/
break;
case RTE_CTE:
/* CTE reference: examine subquery's output expr */
{
CommonTableExpr *cte = NULL;
Index ctelevelsup;
ListCell *lc;
/*
* Try to find the referenced CTE using the namespace stack.
*/
ctelevelsup = rte->ctelevelsup + netlevelsup;
if (ctelevelsup >= list_length(context->namespaces))
lc = NULL;
else
{
deparse_namespace *ctedpns;
ctedpns = (deparse_namespace *)
list_nth(context->namespaces, ctelevelsup);
foreach(lc, ctedpns->ctes)
{
cte = (CommonTableExpr *) lfirst(lc);
if (strcmp(cte->ctename, rte->ctename) == 0)
break;
}
}
if (lc != NULL)
{
Query *ctequery = (Query *) cte->ctequery;
TargetEntry *ste = get_tle_by_resno(GetCTETargetList(cte),
attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
expr = (Node *) ste->expr;
if (IsA(expr, Var))
{
/*
* Recurse into the CTE to see what its Var refers to.
* We have to build an additional level of namespace
* to keep in step with varlevelsup in the CTE.
* Furthermore it could be an outer CTE, so we may
* have to delete some levels of namespace.
*/
List *save_nslist = context->namespaces;
List *new_nslist;
deparse_namespace mydpns;
const char *result;
set_deparse_for_query(&mydpns, ctequery,
context->namespaces);
new_nslist = list_copy_tail(context->namespaces,
ctelevelsup);
context->namespaces = lcons(&mydpns, new_nslist);
result = get_name_for_var_field((Var *) expr, fieldno,
0, context);
context->namespaces = save_nslist;
return result;
}
/* else fall through to inspect the expression */
}
else
{
/*
* We're deparsing a Plan tree so we don't have a CTE
* list. But the only place we'd see a Var directly
* referencing a CTE RTE is in a CteScan plan node, and we
* can look into the subplan's tlist instead.
*/
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
if (!dpns->inner_planstate)
elog(ERROR, "failed to find plan for CTE %s",
rte->eref->aliasname);
tle = get_tle_by_resno(dpns->inner_tlist, attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
pop_child_plan(dpns, &save_dpns);
return result;
}
}
break;
}
/*
* We now have an expression we can't expand any more, so see if
* get_expr_result_type() can do anything with it. If not, pass to
* lookup_rowtype_tupdesc() which will probably fail, but will give an
* appropriate error message while failing.
*/
if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
tupleDesc = lookup_rowtype_tupdesc_copy(exprType(expr),
exprTypmod(expr));
Assert(tupleDesc);
/* Got the tupdesc, so we can extract the field name */
Assert(fieldno >= 1 && fieldno <= tupleDesc->natts);
return NameStr(tupleDesc->attrs[fieldno - 1]->attname);
}
/*
* Try to find the referenced expression for a PARAM_EXEC Param that might
* reference a parameter supplied by an upper NestLoop or SubPlan plan node.
*
* If successful, return the expression and set *dpns_p and *ancestor_cell_p
* appropriately for calling push_ancestor_plan(). If no referent can be
* found, return NULL.
*/
static Node *
find_param_referent(Param *param, deparse_context *context,
deparse_namespace **dpns_p, ListCell **ancestor_cell_p)
{
/* Initialize output parameters to prevent compiler warnings */
*dpns_p = NULL;
*ancestor_cell_p = NULL;
/*
* If it's a PARAM_EXEC parameter, look for a matching NestLoopParam or
* SubPlan argument. This will necessarily be in some ancestor of the
* current expression's PlanState.
*/
if (param->paramkind == PARAM_EXEC)
{
deparse_namespace *dpns;
PlanState *child_ps;
bool in_same_plan_level;
ListCell *lc;
dpns = (deparse_namespace *) linitial(context->namespaces);
child_ps = dpns->planstate;
in_same_plan_level = true;
foreach(lc, dpns->ancestors)
{
PlanState *ps = (PlanState *) lfirst(lc);
ListCell *lc2;
/*
* NestLoops transmit params to their inner child only; also, once
* we've crawled up out of a subplan, this couldn't possibly be
* the right match.
*/
if (IsA(ps, NestLoopState) &&
child_ps == innerPlanState(ps) &&
in_same_plan_level)
{
NestLoop *nl = (NestLoop *) ps->plan;
foreach(lc2, nl->nestParams)
{
NestLoopParam *nlp = (NestLoopParam *) lfirst(lc2);
if (nlp->paramno == param->paramid)
{
/* Found a match, so return it */
*dpns_p = dpns;
*ancestor_cell_p = lc;
return (Node *) nlp->paramval;
}
}
}
/*
* Check to see if we're crawling up from a subplan.
*/
foreach(lc2, ps->subPlan)
{
SubPlanState *sstate = (SubPlanState *) lfirst(lc2);
SubPlan *subplan = (SubPlan *) sstate->xprstate.expr;
ListCell *lc3;
ListCell *lc4;
if (child_ps != sstate->planstate)
continue;
/* Matched subplan, so check its arguments */
forboth(lc3, subplan->parParam, lc4, subplan->args)
{
int paramid = lfirst_int(lc3);
Node *arg = (Node *) lfirst(lc4);
if (paramid == param->paramid)
{
/* Found a match, so return it */
*dpns_p = dpns;
*ancestor_cell_p = lc;
return arg;
}
}
/* Keep looking, but we are emerging from a subplan. */
in_same_plan_level = false;
break;
}
/*
* Likewise check to see if we're emerging from an initplan.
* Initplans never have any parParams, so no need to search that
* list, but we need to know if we should reset
* in_same_plan_level.
*/
foreach(lc2, ps->initPlan)
{
SubPlanState *sstate = (SubPlanState *) lfirst(lc2);
if (child_ps != sstate->planstate)
continue;
/* No parameters to be had here. */
Assert(((SubPlan *) sstate->xprstate.expr)->parParam == NIL);
/* Keep looking, but we are emerging from an initplan. */
in_same_plan_level = false;
break;
}
/* No luck, crawl up to next ancestor */
child_ps = ps;
}
}
/* No referent found */
return NULL;
}
/*
* Display a Param appropriately.
*/
static void
get_parameter(Param *param, deparse_context *context)
{
Node *expr;
deparse_namespace *dpns;
ListCell *ancestor_cell;
/*
* If it's a PARAM_EXEC parameter, try to locate the expression from which
* the parameter was computed. Note that failing to find a referent isn't
* an error, since the Param might well be a subplan output rather than an
* input.
*/
expr = find_param_referent(param, context, &dpns, &ancestor_cell);
if (expr)
{
/* Found a match, so print it */
deparse_namespace save_dpns;
bool save_varprefix;
bool need_paren;
/* Switch attention to the ancestor plan node */
push_ancestor_plan(dpns, ancestor_cell, &save_dpns);
/*
* Force prefixing of Vars, since they won't belong to the relation
* being scanned in the original plan node.
*/
save_varprefix = context->varprefix;
context->varprefix = true;
/*
* A Param's expansion is typically a Var, Aggref, or upper-level
* Param, which wouldn't need extra parentheses. Otherwise, insert
* parens to ensure the expression looks atomic.
*/
need_paren = !(IsA(expr, Var) ||
IsA(expr, Aggref) ||
IsA(expr, Param));
if (need_paren)
appendStringInfoChar(context->buf, '(');
get_rule_expr(expr, context, false);
if (need_paren)
appendStringInfoChar(context->buf, ')');
context->varprefix = save_varprefix;
pop_ancestor_plan(dpns, &save_dpns);
return;
}
/*
* Not PARAM_EXEC, or couldn't find referent: just print $N.
*/
appendStringInfo(context->buf, "$%d", param->paramid);
}
/*
* get_simple_binary_op_name
*
* helper function for isSimpleNode
* will return single char binary operator name, or NULL if it's not
*/
static const char *
get_simple_binary_op_name(OpExpr *expr)
{
List *args = expr->args;
if (list_length(args) == 2)
{
/* binary operator */
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
const char *op;
op = generate_operator_name(expr->opno, exprType(arg1), exprType(arg2));
if (strlen(op) == 1)
return op;
}
return NULL;
}
/*
* isSimpleNode - check if given node is simple (doesn't need parenthesizing)
*
* true : simple in the context of parent node's type
* false : not simple
*/
static bool
isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
{
if (!node)
return false;
switch (nodeTag(node))
{
case T_Var:
case T_Const:
case T_Param:
case T_CoerceToDomainValue:
case T_SetToDefault:
case T_CurrentOfExpr:
/* single words: always simple */
return true;
case T_ArrayRef:
case T_ArrayExpr:
case T_RowExpr:
case T_CoalesceExpr:
case T_MinMaxExpr:
case T_XmlExpr:
case T_NullIfExpr:
case T_Aggref:
case T_WindowFunc:
case T_FuncExpr:
/* function-like: name(..) or name[..] */
return true;
/* CASE keywords act as parentheses */
case T_CaseExpr:
return true;
case T_FieldSelect:
/*
* appears simple since . has top precedence, unless parent is
* T_FieldSelect itself!
*/
return (IsA(parentNode, FieldSelect) ? false : true);
case T_FieldStore:
/*
* treat like FieldSelect (probably doesn't matter)
*/
return (IsA(parentNode, FieldStore) ? false : true);
case T_CoerceToDomain:
/* maybe simple, check args */
return isSimpleNode((Node *) ((CoerceToDomain *) node)->arg,
node, prettyFlags);
case T_RelabelType:
return isSimpleNode((Node *) ((RelabelType *) node)->arg,
node, prettyFlags);
case T_CoerceViaIO:
return isSimpleNode((Node *) ((CoerceViaIO *) node)->arg,
node, prettyFlags);
case T_ArrayCoerceExpr:
return isSimpleNode((Node *) ((ArrayCoerceExpr *) node)->arg,
node, prettyFlags);
case T_ConvertRowtypeExpr:
return isSimpleNode((Node *) ((ConvertRowtypeExpr *) node)->arg,
node, prettyFlags);
case T_OpExpr:
{
/* depends on parent node type; needs further checking */
if (prettyFlags & PRETTYFLAG_PAREN && IsA(parentNode, OpExpr))
{
const char *op;
const char *parentOp;
bool is_lopriop;
bool is_hipriop;
bool is_lopriparent;
bool is_hipriparent;
op = get_simple_binary_op_name((OpExpr *) node);
if (!op)
return false;
/* We know only the basic operators + - and * / % */
is_lopriop = (strchr("+-", *op) != NULL);
is_hipriop = (strchr("*/%", *op) != NULL);
if (!(is_lopriop || is_hipriop))
return false;
parentOp = get_simple_binary_op_name((OpExpr *) parentNode);
if (!parentOp)
return false;
is_lopriparent = (strchr("+-", *parentOp) != NULL);
is_hipriparent = (strchr("*/%", *parentOp) != NULL);
if (!(is_lopriparent || is_hipriparent))
return false;
if (is_hipriop && is_lopriparent)
return true; /* op binds tighter than parent */
if (is_lopriop && is_hipriparent)
return false;
/*
* Operators are same priority --- can skip parens only if
* we have (a - b) - c, not a - (b - c).
*/
if (node == (Node *) linitial(((OpExpr *) parentNode)->args))
return true;
return false;
}
/* else do the same stuff as for T_SubLink et al. */
/* FALL THROUGH */
}
case T_SubLink:
case T_NullTest:
case T_BooleanTest:
case T_DistinctExpr:
switch (nodeTag(parentNode))
{
case T_FuncExpr:
{
/* special handling for casts */
CoercionForm type = ((FuncExpr *) parentNode)->funcformat;
if (type == COERCE_EXPLICIT_CAST ||
type == COERCE_IMPLICIT_CAST)
return false;
return true; /* own parentheses */
}
case T_BoolExpr: /* lower precedence */
case T_ArrayRef: /* other separators */
case T_ArrayExpr: /* other separators */
case T_RowExpr: /* other separators */
case T_CoalesceExpr: /* own parentheses */
case T_MinMaxExpr: /* own parentheses */
case T_XmlExpr: /* own parentheses */
case T_NullIfExpr: /* other separators */
case T_Aggref: /* own parentheses */
case T_WindowFunc: /* own parentheses */
case T_CaseExpr: /* other separators */
return true;
default:
return false;
}
case T_BoolExpr:
switch (nodeTag(parentNode))
{
case T_BoolExpr:
if (prettyFlags & PRETTYFLAG_PAREN)
{
BoolExprType type;
BoolExprType parentType;
type = ((BoolExpr *) node)->boolop;
parentType = ((BoolExpr *) parentNode)->boolop;
switch (type)
{
case NOT_EXPR:
case AND_EXPR:
if (parentType == AND_EXPR || parentType == OR_EXPR)
return true;
break;
case OR_EXPR:
if (parentType == OR_EXPR)
return true;
break;
}
}
return false;
case T_FuncExpr:
{
/* special handling for casts */
CoercionForm type = ((FuncExpr *) parentNode)->funcformat;
if (type == COERCE_EXPLICIT_CAST ||
type == COERCE_IMPLICIT_CAST)
return false;
return true; /* own parentheses */
}
case T_ArrayRef: /* other separators */
case T_ArrayExpr: /* other separators */
case T_RowExpr: /* other separators */
case T_CoalesceExpr: /* own parentheses */
case T_MinMaxExpr: /* own parentheses */
case T_XmlExpr: /* own parentheses */
case T_NullIfExpr: /* other separators */
case T_Aggref: /* own parentheses */
case T_WindowFunc: /* own parentheses */
case T_CaseExpr: /* other separators */
return true;
default:
return false;
}
default:
break;
}
/* those we don't know: in dubio complexo */
return false;
}
/*
* appendContextKeyword - append a keyword to buffer
*
* If prettyPrint is enabled, perform a line break, and adjust indentation.
* Otherwise, just append the keyword.
*/
static void
appendContextKeyword(deparse_context *context, const char *str,
int indentBefore, int indentAfter, int indentPlus)
{
StringInfo buf = context->buf;
if (PRETTY_INDENT(context))
{
int indentAmount;
context->indentLevel += indentBefore;
/* remove any trailing spaces currently in the buffer ... */
removeStringInfoSpaces(buf);
/* ... then add a newline and some spaces */
appendStringInfoChar(buf, '\n');
if (context->indentLevel < PRETTYINDENT_LIMIT)
indentAmount = Max(context->indentLevel, 0) + indentPlus;
else
{
/*
* If we're indented more than PRETTYINDENT_LIMIT characters, try
* to conserve horizontal space by reducing the per-level
* indentation. For best results the scale factor here should
* divide all the indent amounts that get added to indentLevel
* (PRETTYINDENT_STD, etc). It's important that the indentation
* not grow unboundedly, else deeply-nested trees use O(N^2)
* whitespace; so we also wrap modulo PRETTYINDENT_LIMIT.
*/
indentAmount = PRETTYINDENT_LIMIT +
(context->indentLevel - PRETTYINDENT_LIMIT) /
(PRETTYINDENT_STD / 2);
indentAmount %= PRETTYINDENT_LIMIT;
/* scale/wrap logic affects indentLevel, but not indentPlus */
indentAmount += indentPlus;
}
appendStringInfoSpaces(buf, indentAmount);
appendStringInfoString(buf, str);
context->indentLevel += indentAfter;
if (context->indentLevel < 0)
context->indentLevel = 0;
}
else
appendStringInfoString(buf, str);
}
/*
* removeStringInfoSpaces - delete trailing spaces from a buffer.
*
* Possibly this should move to stringinfo.c at some point.
*/
static void
removeStringInfoSpaces(StringInfo str)
{
while (str->len > 0 && str->data[str->len - 1] == ' ')
str->data[--(str->len)] = '\0';
}
/*
* get_rule_expr_paren - deparse expr using get_rule_expr,
* embracing the string with parentheses if necessary for prettyPrint.
*
* Never embrace if prettyFlags=0, because it's done in the calling node.
*
* Any node that does *not* embrace its argument node by sql syntax (with
* parentheses, non-operator keywords like CASE/WHEN/ON, or comma etc) should
* use get_rule_expr_paren instead of get_rule_expr so parentheses can be
* added.
*/
static void
get_rule_expr_paren(Node *node, deparse_context *context,
bool showimplicit, Node *parentNode)
{
bool need_paren;
need_paren = PRETTY_PAREN(context) &&
!isSimpleNode(node, parentNode, context->prettyFlags);
if (need_paren)
appendStringInfoChar(context->buf, '(');
get_rule_expr(node, context, showimplicit);
if (need_paren)
appendStringInfoChar(context->buf, ')');
}
/* ----------
* get_rule_expr - Parse back an expression
*
* Note: showimplicit determines whether we display any implicit cast that
* is present at the top of the expression tree. It is a passed argument,
* not a field of the context struct, because we change the value as we
* recurse down into the expression. In general we suppress implicit casts
* when the result type is known with certainty (eg, the arguments of an
* OR must be boolean). We display implicit casts for arguments of functions
* and operators, since this is needed to be certain that the same function
* or operator will be chosen when the expression is re-parsed.
* ----------
*/
static void
get_rule_expr(Node *node, deparse_context *context,
bool showimplicit)
{
StringInfo buf = context->buf;
if (node == NULL)
return;
/* Guard against excessively long or deeply-nested queries */
CHECK_FOR_INTERRUPTS();
check_stack_depth();
/*
* Each level of get_rule_expr must emit an indivisible term
* (parenthesized if necessary) to ensure result is reparsed into the same
* expression tree. The only exception is that when the input is a List,
* we emit the component items comma-separated with no surrounding
* decoration; this is convenient for most callers.
*/
switch (nodeTag(node))
{
case T_Var:
(void) get_variable((Var *) node, 0, false, context);
break;
case T_Const:
get_const_expr((Const *) node, context, 0);
break;
case T_Param:
get_parameter((Param *) node, context);
break;
case T_Aggref:
get_agg_expr((Aggref *) node, context, (Aggref *) node);
break;
case T_GroupingFunc:
{
GroupingFunc *gexpr = (GroupingFunc *) node;
appendStringInfoString(buf, "GROUPING(");
get_rule_expr((Node *) gexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_WindowFunc:
get_windowfunc_expr((WindowFunc *) node, context);
break;
case T_ArrayRef:
{
ArrayRef *aref = (ArrayRef *) node;
bool need_parens;
/*
* If the argument is a CaseTestExpr, we must be inside a
* FieldStore, ie, we are assigning to an element of an array
* within a composite column. Since we already punted on
* displaying the FieldStore's target information, just punt
* here too, and display only the assignment source
* expression.
*/
if (IsA(aref->refexpr, CaseTestExpr))
{
Assert(aref->refassgnexpr);
get_rule_expr((Node *) aref->refassgnexpr,
context, showimplicit);
break;
}
/*
* Parenthesize the argument unless it's a simple Var or a
* FieldSelect. (In particular, if it's another ArrayRef, we
* *must* parenthesize to avoid confusion.)
*/
need_parens = !IsA(aref->refexpr, Var) &&
!IsA(aref->refexpr, FieldSelect);
if (need_parens)
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) aref->refexpr, context, showimplicit);
if (need_parens)
appendStringInfoChar(buf, ')');
/*
* If there's a refassgnexpr, we want to print the node in the
* format "array[subscripts] := refassgnexpr". This is not
* legal SQL, so decompilation of INSERT or UPDATE statements
* should always use processIndirection as part of the
* statement-level syntax. We should only see this when
* EXPLAIN tries to print the targetlist of a plan resulting
* from such a statement.
*/
if (aref->refassgnexpr)
{
Node *refassgnexpr;
/*
* Use processIndirection to print this node's subscripts
* as well as any additional field selections or
* subscripting in immediate descendants. It returns the
* RHS expr that is actually being "assigned".
*/
refassgnexpr = processIndirection(node, context, true);
appendStringInfoString(buf, " := ");
get_rule_expr(refassgnexpr, context, showimplicit);
}
else
{
/* Just an ordinary array fetch, so print subscripts */
printSubscripts(aref, context);
}
}
break;
case T_FuncExpr:
get_func_expr((FuncExpr *) node, context, showimplicit);
break;
case T_NamedArgExpr:
{
NamedArgExpr *na = (NamedArgExpr *) node;
appendStringInfo(buf, "%s => ", quote_identifier(na->name));
get_rule_expr((Node *) na->arg, context, showimplicit);
}
break;
case T_OpExpr:
get_oper_expr((OpExpr *) node, context);
break;
case T_DistinctExpr:
{
DistinctExpr *expr = (DistinctExpr *) node;
List *args = expr->args;
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg1, context, true, node);
appendStringInfoString(buf, " IS DISTINCT FROM ");
get_rule_expr_paren(arg2, context, true, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_NullIfExpr:
{
NullIfExpr *nullifexpr = (NullIfExpr *) node;
appendStringInfoString(buf, "NULLIF(");
get_rule_expr((Node *) nullifexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
List *args = expr->args;
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg1, context, true, node);
appendStringInfo(buf, " %s %s (",
generate_operator_name(expr->opno,
exprType(arg1),
get_base_element_type(exprType(arg2))),
expr->useOr ? "ANY" : "ALL");
get_rule_expr_paren(arg2, context, true, node);
/*
* There's inherent ambiguity in "x op ANY/ALL (y)" when y is
* a bare sub-SELECT. Since we're here, the sub-SELECT must
* be meant as a scalar sub-SELECT yielding an array value to
* be used in ScalarArrayOpExpr; but the grammar will
* preferentially interpret such a construct as an ANY/ALL
* SubLink. To prevent misparsing the output that way, insert
* a dummy coercion (which will be stripped by parse analysis,
* so no inefficiency is added in dump and reload). This is
* indeed most likely what the user wrote to get the construct
* accepted in the first place.
*/
if (IsA(arg2, SubLink) &&
((SubLink *) arg2)->subLinkType == EXPR_SUBLINK)
appendStringInfo(buf, "::%s",
format_type_with_typemod(exprType(arg2),
exprTypmod(arg2)));
appendStringInfoChar(buf, ')');
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_BoolExpr:
{
BoolExpr *expr = (BoolExpr *) node;
Node *first_arg = linitial(expr->args);
ListCell *arg = lnext(list_head(expr->args));
switch (expr->boolop)
{
case AND_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(first_arg, context,
false, node);
while (arg)
{
appendStringInfoString(buf, " AND ");
get_rule_expr_paren((Node *) lfirst(arg), context,
false, node);
arg = lnext(arg);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
case OR_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(first_arg, context,
false, node);
while (arg)
{
appendStringInfoString(buf, " OR ");
get_rule_expr_paren((Node *) lfirst(arg), context,
false, node);
arg = lnext(arg);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
case NOT_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
appendStringInfoString(buf, "NOT ");
get_rule_expr_paren(first_arg, context,
false, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
default:
elog(ERROR, "unrecognized boolop: %d",
(int) expr->boolop);
}
}
break;
case T_SubLink:
get_sublink_expr((SubLink *) node, context);
break;
case T_SubPlan:
{
SubPlan *subplan = (SubPlan *) node;
/*
* We cannot see an already-planned subplan in rule deparsing,
* only while EXPLAINing a query plan. We don't try to
* reconstruct the original SQL, just reference the subplan
* that appears elsewhere in EXPLAIN's result.
*/
if (subplan->useHashTable)
appendStringInfo(buf, "(hashed %s)", subplan->plan_name);
else
appendStringInfo(buf, "(%s)", subplan->plan_name);
}
break;
case T_AlternativeSubPlan:
{
AlternativeSubPlan *asplan = (AlternativeSubPlan *) node;
ListCell *lc;
/* As above, this can only happen during EXPLAIN */
appendStringInfoString(buf, "(alternatives: ");
foreach(lc, asplan->subplans)
{
SubPlan *splan = (SubPlan *) lfirst(lc);
Assert(IsA(splan, SubPlan));
if (splan->useHashTable)
appendStringInfo(buf, "hashed %s", splan->plan_name);
else
appendStringInfoString(buf, splan->plan_name);
if (lnext(lc))
appendStringInfoString(buf, " or ");
}
appendStringInfoChar(buf, ')');
}
break;
case T_FieldSelect:
{
FieldSelect *fselect = (FieldSelect *) node;
Node *arg = (Node *) fselect->arg;
int fno = fselect->fieldnum;
const char *fieldname;
bool need_parens;
/*
* Parenthesize the argument unless it's an ArrayRef or
* another FieldSelect. Note in particular that it would be
* WRONG to not parenthesize a Var argument; simplicity is not
* the issue here, having the right number of names is.
*/
need_parens = !IsA(arg, ArrayRef) &&!IsA(arg, FieldSelect);
if (need_parens)
appendStringInfoChar(buf, '(');
get_rule_expr(arg, context, true);
if (need_parens)
appendStringInfoChar(buf, ')');
/*
* Get and print the field name.
*/
fieldname = get_name_for_var_field((Var *) arg, fno,
0, context);
appendStringInfo(buf, ".%s", quote_identifier(fieldname));
}
break;
case T_FieldStore:
{
FieldStore *fstore = (FieldStore *) node;
bool need_parens;
/*
* There is no good way to represent a FieldStore as real SQL,
* so decompilation of INSERT or UPDATE statements should
* always use processIndirection as part of the
* statement-level syntax. We should only get here when
* EXPLAIN tries to print the targetlist of a plan resulting
* from such a statement. The plan case is even harder than
* ordinary rules would be, because the planner tries to
* collapse multiple assignments to the same field or subfield
* into one FieldStore; so we can see a list of target fields
* not just one, and the arguments could be FieldStores
* themselves. We don't bother to try to print the target
* field names; we just print the source arguments, with a
* ROW() around them if there's more than one. This isn't
* terribly complete, but it's probably good enough for
* EXPLAIN's purposes; especially since anything more would be
* either hopelessly confusing or an even poorer
* representation of what the plan is actually doing.
*/
need_parens = (list_length(fstore->newvals) != 1);
if (need_parens)
appendStringInfoString(buf, "ROW(");
get_rule_expr((Node *) fstore->newvals, context, showimplicit);
if (need_parens)
appendStringInfoChar(buf, ')');
}
break;
case T_RelabelType:
{
RelabelType *relabel = (RelabelType *) node;
Node *arg = (Node *) relabel->arg;
if (relabel->relabelformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else
{
get_coercion_expr(arg, context,
relabel->resulttype,
relabel->resulttypmod,
node);
}
}
break;
case T_CoerceViaIO:
{
CoerceViaIO *iocoerce = (CoerceViaIO *) node;
Node *arg = (Node *) iocoerce->arg;
if (iocoerce->coerceformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else
{
get_coercion_expr(arg, context,
iocoerce->resulttype,
-1,
node);
}
}
break;
case T_ArrayCoerceExpr:
{
ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node;
Node *arg = (Node *) acoerce->arg;
if (acoerce->coerceformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else
{
get_coercion_expr(arg, context,
acoerce->resulttype,
acoerce->resulttypmod,
node);
}
}
break;
case T_ConvertRowtypeExpr:
{
ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) node;
Node *arg = (Node *) convert->arg;
if (convert->convertformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else
{
get_coercion_expr(arg, context,
convert->resulttype, -1,
node);
}
}
break;
case T_CollateExpr:
{
CollateExpr *collate = (CollateExpr *) node;
Node *arg = (Node *) collate->arg;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, showimplicit, node);
appendStringInfo(buf, " COLLATE %s",
generate_collation_name(collate->collOid));
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_CaseExpr:
{
CaseExpr *caseexpr = (CaseExpr *) node;
ListCell *temp;
appendContextKeyword(context, "CASE",
0, PRETTYINDENT_VAR, 0);
if (caseexpr->arg)
{
appendStringInfoChar(buf, ' ');
get_rule_expr((Node *) caseexpr->arg, context, true);
}
foreach(temp, caseexpr->args)
{
CaseWhen *when = (CaseWhen *) lfirst(temp);
Node *w = (Node *) when->expr;
if (caseexpr->arg)
{
/*
* The parser should have produced WHEN clauses of the
* form "CaseTestExpr = RHS", possibly with an
* implicit coercion inserted above the CaseTestExpr.
* For accurate decompilation of rules it's essential
* that we show just the RHS. However in an
* expression that's been through the optimizer, the
* WHEN clause could be almost anything (since the
* equality operator could have been expanded into an
* inline function). If we don't recognize the form
* of the WHEN clause, just punt and display it as-is.
*/
if (IsA(w, OpExpr))
{
List *args = ((OpExpr *) w)->args;
if (list_length(args) == 2 &&
IsA(strip_implicit_coercions(linitial(args)),
CaseTestExpr))
w = (Node *) lsecond(args);
}
}
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "WHEN ",
0, 0, 0);
get_rule_expr(w, context, false);
appendStringInfoString(buf, " THEN ");
get_rule_expr((Node *) when->result, context, true);
}
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "ELSE ",
0, 0, 0);
get_rule_expr((Node *) caseexpr->defresult, context, true);
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "END",
-PRETTYINDENT_VAR, 0, 0);
}
break;
case T_CaseTestExpr:
{
/*
* Normally we should never get here, since for expressions
* that can contain this node type we attempt to avoid
* recursing to it. But in an optimized expression we might
* be unable to avoid that (see comments for CaseExpr). If we
* do see one, print it as CASE_TEST_EXPR.
*/
appendStringInfoString(buf, "CASE_TEST_EXPR");
}
break;
case T_ArrayExpr:
{
ArrayExpr *arrayexpr = (ArrayExpr *) node;
appendStringInfoString(buf, "ARRAY[");
get_rule_expr((Node *) arrayexpr->elements, context, true);
appendStringInfoChar(buf, ']');
/*
* If the array isn't empty, we assume its elements are
* coerced to the desired type. If it's empty, though, we
* need an explicit coercion to the array type.
*/
if (arrayexpr->elements == NIL)
appendStringInfo(buf, "::%s",
format_type_with_typemod(arrayexpr->array_typeid, -1));
}
break;
case T_RowExpr:
{
RowExpr *rowexpr = (RowExpr *) node;
TupleDesc tupdesc = NULL;
ListCell *arg;
int i;
char *sep;
/*
* If it's a named type and not RECORD, we may have to skip
* dropped columns and/or claim there are NULLs for added
* columns.
*/
if (rowexpr->row_typeid != RECORDOID)
{
tupdesc = lookup_rowtype_tupdesc(rowexpr->row_typeid, -1);
Assert(list_length(rowexpr->args) <= tupdesc->natts);
}
/*
* SQL99 allows "ROW" to be omitted when there is more than
* one column, but for simplicity we always print it.
*/
appendStringInfoString(buf, "ROW(");
sep = "";
i = 0;
foreach(arg, rowexpr->args)
{
Node *e = (Node *) lfirst(arg);
if (tupdesc == NULL ||
!tupdesc->attrs[i]->attisdropped)
{
appendStringInfoString(buf, sep);
/* Whole-row Vars need special treatment here */
get_rule_expr_toplevel(e, context, true);
sep = ", ";
}
i++;
}
if (tupdesc != NULL)
{
while (i < tupdesc->natts)
{
if (!tupdesc->attrs[i]->attisdropped)
{
appendStringInfoString(buf, sep);
appendStringInfoString(buf, "NULL");
sep = ", ";
}
i++;
}
ReleaseTupleDesc(tupdesc);
}
appendStringInfoChar(buf, ')');
if (rowexpr->row_format == COERCE_EXPLICIT_CAST)
appendStringInfo(buf, "::%s",
format_type_with_typemod(rowexpr->row_typeid, -1));
}
break;
case T_RowCompareExpr:
{
RowCompareExpr *rcexpr = (RowCompareExpr *) node;
ListCell *arg;
char *sep;
/*
* SQL99 allows "ROW" to be omitted when there is more than
* one column, but for simplicity we always print it.
*/
appendStringInfoString(buf, "(ROW(");
sep = "";
foreach(arg, rcexpr->largs)
{
Node *e = (Node *) lfirst(arg);
appendStringInfoString(buf, sep);
get_rule_expr(e, context, true);
sep = ", ";
}
/*
* We assume that the name of the first-column operator will
* do for all the rest too. This is definitely open to
* failure, eg if some but not all operators were renamed
* since the construct was parsed, but there seems no way to
* be perfect.
*/
appendStringInfo(buf, ") %s ROW(",
generate_operator_name(linitial_oid(rcexpr->opnos),
exprType(linitial(rcexpr->largs)),
exprType(linitial(rcexpr->rargs))));
sep = "";
foreach(arg, rcexpr->rargs)
{
Node *e = (Node *) lfirst(arg);
appendStringInfoString(buf, sep);
get_rule_expr(e, context, true);
sep = ", ";
}
appendStringInfoString(buf, "))");
}
break;
case T_CoalesceExpr:
{
CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
appendStringInfoString(buf, "COALESCE(");
get_rule_expr((Node *) coalesceexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_MinMaxExpr:
{
MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
switch (minmaxexpr->op)
{
case IS_GREATEST:
appendStringInfoString(buf, "GREATEST(");
break;
case IS_LEAST:
appendStringInfoString(buf, "LEAST(");
break;
}
get_rule_expr((Node *) minmaxexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
bool needcomma = false;
ListCell *arg;
ListCell *narg;
Const *con;
switch (xexpr->op)
{
case IS_XMLCONCAT:
appendStringInfoString(buf, "XMLCONCAT(");
break;
case IS_XMLELEMENT:
appendStringInfoString(buf, "XMLELEMENT(");
break;
case IS_XMLFOREST:
appendStringInfoString(buf, "XMLFOREST(");
break;
case IS_XMLPARSE:
appendStringInfoString(buf, "XMLPARSE(");
break;
case IS_XMLPI:
appendStringInfoString(buf, "XMLPI(");
break;
case IS_XMLROOT:
appendStringInfoString(buf, "XMLROOT(");
break;
case IS_XMLSERIALIZE:
appendStringInfoString(buf, "XMLSERIALIZE(");
break;
case IS_DOCUMENT:
break;
}
if (xexpr->op == IS_XMLPARSE || xexpr->op == IS_XMLSERIALIZE)
{
if (xexpr->xmloption == XMLOPTION_DOCUMENT)
appendStringInfoString(buf, "DOCUMENT ");
else
appendStringInfoString(buf, "CONTENT ");
}
if (xexpr->name)
{
appendStringInfo(buf, "NAME %s",
quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
needcomma = true;
}
if (xexpr->named_args)
{
if (xexpr->op != IS_XMLFOREST)
{
if (needcomma)
appendStringInfoString(buf, ", ");
appendStringInfoString(buf, "XMLATTRIBUTES(");
needcomma = false;
}
forboth(arg, xexpr->named_args, narg, xexpr->arg_names)
{
Node *e = (Node *) lfirst(arg);
char *argname = strVal(lfirst(narg));
if (needcomma)
appendStringInfoString(buf, ", ");
get_rule_expr((Node *) e, context, true);
appendStringInfo(buf, " AS %s",
quote_identifier(map_xml_name_to_sql_identifier(argname)));
needcomma = true;
}
if (xexpr->op != IS_XMLFOREST)
appendStringInfoChar(buf, ')');
}
if (xexpr->args)
{
if (needcomma)
appendStringInfoString(buf, ", ");
switch (xexpr->op)
{
case IS_XMLCONCAT:
case IS_XMLELEMENT:
case IS_XMLFOREST:
case IS_XMLPI:
case IS_XMLSERIALIZE:
/* no extra decoration needed */
get_rule_expr((Node *) xexpr->args, context, true);
break;
case IS_XMLPARSE:
Assert(list_length(xexpr->args) == 2);
get_rule_expr((Node *) linitial(xexpr->args),
context, true);
con = (Const *) lsecond(xexpr->args);
Assert(IsA(con, Const));
Assert(!con->constisnull);
if (DatumGetBool(con->constvalue))
appendStringInfoString(buf,
" PRESERVE WHITESPACE");
else
appendStringInfoString(buf,
" STRIP WHITESPACE");
break;
case IS_XMLROOT:
Assert(list_length(xexpr->args) == 3);
get_rule_expr((Node *) linitial(xexpr->args),
context, true);
appendStringInfoString(buf, ", VERSION ");
con = (Const *) lsecond(xexpr->args);
if (IsA(con, Const) &&
con->constisnull)
appendStringInfoString(buf, "NO VALUE");
else
get_rule_expr((Node *) con, context, false);
con = (Const *) lthird(xexpr->args);
Assert(IsA(con, Const));
if (con->constisnull)
/* suppress STANDALONE NO VALUE */ ;
else
{
switch (DatumGetInt32(con->constvalue))
{
case XML_STANDALONE_YES:
appendStringInfoString(buf,
", STANDALONE YES");
break;
case XML_STANDALONE_NO:
appendStringInfoString(buf,
", STANDALONE NO");
break;
case XML_STANDALONE_NO_VALUE:
appendStringInfoString(buf,
", STANDALONE NO VALUE");
break;
default:
break;
}
}
break;
case IS_DOCUMENT:
get_rule_expr_paren((Node *) xexpr->args, context, false, node);
break;
}
}
if (xexpr->op == IS_XMLSERIALIZE)
appendStringInfo(buf, " AS %s",
format_type_with_typemod(xexpr->type,
xexpr->typmod));
if (xexpr->op == IS_DOCUMENT)
appendStringInfoString(buf, " IS DOCUMENT");
else
appendStringInfoChar(buf, ')');
}
break;
case T_NullTest:
{
NullTest *ntest = (NullTest *) node;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren((Node *) ntest->arg, context, true, node);
switch (ntest->nulltesttype)
{
case IS_NULL:
appendStringInfoString(buf, " IS NULL");
break;
case IS_NOT_NULL:
appendStringInfoString(buf, " IS NOT NULL");
break;
default:
elog(ERROR, "unrecognized nulltesttype: %d",
(int) ntest->nulltesttype);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_BooleanTest:
{
BooleanTest *btest = (BooleanTest *) node;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren((Node *) btest->arg, context, false, node);
switch (btest->booltesttype)
{
case IS_TRUE:
appendStringInfoString(buf, " IS TRUE");
break;
case IS_NOT_TRUE:
appendStringInfoString(buf, " IS NOT TRUE");
break;
case IS_FALSE:
appendStringInfoString(buf, " IS FALSE");
break;
case IS_NOT_FALSE:
appendStringInfoString(buf, " IS NOT FALSE");
break;
case IS_UNKNOWN:
appendStringInfoString(buf, " IS UNKNOWN");
break;
case IS_NOT_UNKNOWN:
appendStringInfoString(buf, " IS NOT UNKNOWN");
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) btest->booltesttype);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_CoerceToDomain:
{
CoerceToDomain *ctest = (CoerceToDomain *) node;
Node *arg = (Node *) ctest->arg;
if (ctest->coercionformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr(arg, context, false);
}
else
{
get_coercion_expr(arg, context,
ctest->resulttype,
ctest->resulttypmod,
node);
}
}
break;
case T_CoerceToDomainValue:
appendStringInfoString(buf, "VALUE");
break;
case T_SetToDefault:
appendStringInfoString(buf, "DEFAULT");
break;
case T_CurrentOfExpr:
{
CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
if (cexpr->cursor_name)
appendStringInfo(buf, "CURRENT OF %s",
quote_identifier(cexpr->cursor_name));
else
appendStringInfo(buf, "CURRENT OF $%d",
cexpr->cursor_param);
}
break;
case T_InferenceElem:
{
InferenceElem *iexpr = (InferenceElem *) node;
bool save_varprefix;
bool need_parens;
/*
* InferenceElem can only refer to target relation, so a
* prefix is not useful, and indeed would cause parse errors.
*/
save_varprefix = context->varprefix;
context->varprefix = false;
/*
* Parenthesize the element unless it's a simple Var or a bare
* function call. Follows pg_get_indexdef_worker().
*/
need_parens = !IsA(iexpr->expr, Var);
if (IsA(iexpr->expr, FuncExpr) &&
((FuncExpr *) iexpr->expr)->funcformat ==
COERCE_EXPLICIT_CALL)
need_parens = false;
if (need_parens)
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) iexpr->expr,
context, false);
if (need_parens)
appendStringInfoChar(buf, ')');
context->varprefix = save_varprefix;
if (iexpr->infercollid)
appendStringInfo(buf, " COLLATE %s",
generate_collation_name(iexpr->infercollid));
/* Add the operator class name, if not default */
if (iexpr->inferopclass)
{
Oid inferopclass = iexpr->inferopclass;
Oid inferopcinputtype = get_opclass_input_type(iexpr->inferopclass);
get_opclass_name(inferopclass, inferopcinputtype, buf);
}
}
break;
case T_List:
{
char *sep;
ListCell *l;
sep = "";
foreach(l, (List *) node)
{
appendStringInfoString(buf, sep);
get_rule_expr((Node *) lfirst(l), context, showimplicit);
sep = ", ";
}
}
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
break;
}
}
/*
* get_rule_expr_toplevel - Parse back a toplevel expression
*
* Same as get_rule_expr(), except that if the expr is just a Var, we pass
* istoplevel = true not false to get_variable(). This causes whole-row Vars
* to get printed with decoration that will prevent expansion of "*".
* We need to use this in contexts such as ROW() and VALUES(), where the
* parser would expand "foo.*" appearing at top level. (In principle we'd
* use this in get_target_list() too, but that has additional worries about
* whether to print AS, so it needs to invoke get_variable() directly anyway.)
*/
static void
get_rule_expr_toplevel(Node *node, deparse_context *context,
bool showimplicit)
{
if (node && IsA(node, Var))
(void) get_variable((Var *) node, 0, true, context);
else
get_rule_expr(node, context, showimplicit);
}
/*
* get_oper_expr - Parse back an OpExpr node
*/
static void
get_oper_expr(OpExpr *expr, deparse_context *context)
{
StringInfo buf = context->buf;
Oid opno = expr->opno;
List *args = expr->args;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
if (list_length(args) == 2)
{
/* binary operator */
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
get_rule_expr_paren(arg1, context, true, (Node *) expr);
appendStringInfo(buf, " %s ",
generate_operator_name(opno,
exprType(arg1),
exprType(arg2)));
get_rule_expr_paren(arg2, context, true, (Node *) expr);
}
else
{
/* unary operator --- but which side? */
Node *arg = (Node *) linitial(args);
HeapTuple tp;
Form_pg_operator optup;
tp = SearchSysCache1(OPEROID, ObjectIdGetDatum(opno));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for operator %u", opno);
optup = (Form_pg_operator) GETSTRUCT(tp);
switch (optup->oprkind)
{
case 'l':
appendStringInfo(buf, "%s ",
generate_operator_name(opno,
InvalidOid,
exprType(arg)));
get_rule_expr_paren(arg, context, true, (Node *) expr);
break;
case 'r':
get_rule_expr_paren(arg, context, true, (Node *) expr);
appendStringInfo(buf, " %s",
generate_operator_name(opno,
exprType(arg),
InvalidOid));
break;
default:
elog(ERROR, "bogus oprkind: %d", optup->oprkind);
}
ReleaseSysCache(tp);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
/*
* get_func_expr - Parse back a FuncExpr node
*/
static void
get_func_expr(FuncExpr *expr, deparse_context *context,
bool showimplicit)
{
StringInfo buf = context->buf;
Oid funcoid = expr->funcid;
Oid argtypes[FUNC_MAX_ARGS];
int nargs;
List *argnames;
bool use_variadic;
ListCell *l;
/*
* If the function call came from an implicit coercion, then just show the
* first argument --- unless caller wants to see implicit coercions.
*/
if (expr->funcformat == COERCE_IMPLICIT_CAST && !showimplicit)
{
get_rule_expr_paren((Node *) linitial(expr->args), context,
false, (Node *) expr);
return;
}
/*
* If the function call came from a cast, then show the first argument
* plus an explicit cast operation.
*/
if (expr->funcformat == COERCE_EXPLICIT_CAST ||
expr->funcformat == COERCE_IMPLICIT_CAST)
{
Node *arg = linitial(expr->args);
Oid rettype = expr->funcresulttype;
int32 coercedTypmod;
/* Get the typmod if this is a length-coercion function */
(void) exprIsLengthCoercion((Node *) expr, &coercedTypmod);
get_coercion_expr(arg, context,
rettype, coercedTypmod,
(Node *) expr);
return;
}
/*
* Normal function: display as proname(args). First we need to extract
* the argument datatypes.
*/
if (list_length(expr->args) > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
errmsg("too many arguments")));
nargs = 0;
argnames = NIL;
foreach(l, expr->args)
{
Node *arg = (Node *) lfirst(l);
if (IsA(arg, NamedArgExpr))
argnames = lappend(argnames, ((NamedArgExpr *) arg)->name);
argtypes[nargs] = exprType(arg);
nargs++;
}
appendStringInfo(buf, "%s(",
generate_function_name(funcoid, nargs,
argnames, argtypes,
expr->funcvariadic,
&use_variadic,
context->special_exprkind));
nargs = 0;
foreach(l, expr->args)
{
if (nargs++ > 0)
appendStringInfoString(buf, ", ");
if (use_variadic && lnext(l) == NULL)
appendStringInfoString(buf, "VARIADIC ");
get_rule_expr((Node *) lfirst(l), context, true);
}
appendStringInfoChar(buf, ')');
}
/*
* get_agg_expr - Parse back an Aggref node
*/
static void
get_agg_expr(Aggref *aggref, deparse_context *context,
Aggref *original_aggref)
{
StringInfo buf = context->buf;
Oid argtypes[FUNC_MAX_ARGS];
int nargs;
bool use_variadic;
/*
* For a combining aggregate, we look up and deparse the corresponding
* partial aggregate instead. This is necessary because our input
* argument list has been replaced; the new argument list always has just
* one element, which will point to a partial Aggref that supplies us with
* transition states to combine.
*/
if (DO_AGGSPLIT_COMBINE(aggref->aggsplit))
{
TargetEntry *tle = linitial(aggref->args);
Assert(list_length(aggref->args) == 1);
Assert(IsA(tle, TargetEntry));
resolve_special_varno((Node *) tle->expr, context, original_aggref,
get_agg_combine_expr);
return;
}
/*
* Mark as PARTIAL, if appropriate. We look to the original aggref so as
* to avoid printing this when recursing from the code just above.
*/
if (DO_AGGSPLIT_SKIPFINAL(original_aggref->aggsplit))
appendStringInfoString(buf, "PARTIAL ");
/* Extract the argument types as seen by the parser */
nargs = get_aggregate_argtypes(aggref, argtypes);
/* Print the aggregate name, schema-qualified if needed */
appendStringInfo(buf, "%s(%s",
generate_function_name(aggref->aggfnoid, nargs,
NIL, argtypes,
aggref->aggvariadic,
&use_variadic,
context->special_exprkind),
(aggref->aggdistinct != NIL) ? "DISTINCT " : "");
if (AGGKIND_IS_ORDERED_SET(aggref->aggkind))
{
/*
* Ordered-set aggregates do not use "*" syntax. Also, we needn't
* worry about inserting VARIADIC. So we can just dump the direct
* args as-is.
*/
Assert(!aggref->aggvariadic);
get_rule_expr((Node *) aggref->aggdirectargs, context, true);
Assert(aggref->aggorder != NIL);
appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
get_rule_orderby(aggref->aggorder, aggref->args, false, context);
}
else
{
/* aggstar can be set only in zero-argument aggregates */
if (aggref->aggstar)
appendStringInfoChar(buf, '*');
else
{
ListCell *l;
int i;
i = 0;
foreach(l, aggref->args)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *arg = (Node *) tle->expr;
Assert(!IsA(arg, NamedArgExpr));
if (tle->resjunk)
continue;
if (i++ > 0)
appendStringInfoString(buf, ", ");
if (use_variadic && i == nargs)
appendStringInfoString(buf, "VARIADIC ");
get_rule_expr(arg, context, true);
}
}
if (aggref->aggorder != NIL)
{
appendStringInfoString(buf, " ORDER BY ");
get_rule_orderby(aggref->aggorder, aggref->args, false, context);
}
}
if (aggref->aggfilter != NULL)
{
appendStringInfoString(buf, ") FILTER (WHERE ");
get_rule_expr((Node *) aggref->aggfilter, context, false);
}
appendStringInfoChar(buf, ')');
}
/*
* This is a helper function for get_agg_expr(). It's used when we deparse
* a combining Aggref; resolve_special_varno locates the corresponding partial
* Aggref and then calls this.
*/
static void
get_agg_combine_expr(Node *node, deparse_context *context, void *private)
{
Aggref *aggref;
Aggref *original_aggref = private;
if (!IsA(node, Aggref))
elog(ERROR, "combining Aggref does not point to an Aggref");
aggref = (Aggref *) node;
get_agg_expr(aggref, context, original_aggref);
}
/*
* get_windowfunc_expr - Parse back a WindowFunc node
*/
static void
get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context)
{
StringInfo buf = context->buf;
Oid argtypes[FUNC_MAX_ARGS];
int nargs;
List *argnames;
ListCell *l;
if (list_length(wfunc->args) > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
errmsg("too many arguments")));
nargs = 0;
argnames = NIL;
foreach(l, wfunc->args)
{
Node *arg = (Node *) lfirst(l);
if (IsA(arg, NamedArgExpr))
argnames = lappend(argnames, ((NamedArgExpr *) arg)->name);
argtypes[nargs] = exprType(arg);
nargs++;
}
appendStringInfo(buf, "%s(",
generate_function_name(wfunc->winfnoid, nargs,
argnames, argtypes,
false, NULL,
context->special_exprkind));
/* winstar can be set only in zero-argument aggregates */
if (wfunc->winstar)
appendStringInfoChar(buf, '*');
else
get_rule_expr((Node *) wfunc->args, context, true);
if (wfunc->aggfilter != NULL)
{
appendStringInfoString(buf, ") FILTER (WHERE ");
get_rule_expr((Node *) wfunc->aggfilter, context, false);
}
appendStringInfoString(buf, ") OVER ");
foreach(l, context->windowClause)
{
WindowClause *wc = (WindowClause *) lfirst(l);
if (wc->winref == wfunc->winref)
{
if (wc->name)
appendStringInfoString(buf, quote_identifier(wc->name));
else
get_rule_windowspec(wc, context->windowTList, context);
break;
}
}
if (l == NULL)
{
if (context->windowClause)
elog(ERROR, "could not find window clause for winref %u",
wfunc->winref);
/*
* In EXPLAIN, we don't have window context information available, so
* we have to settle for this:
*/
appendStringInfoString(buf, "(?)");
}
}
/* ----------
* get_coercion_expr
*
* Make a string representation of a value coerced to a specific type
* ----------
*/
static void
get_coercion_expr(Node *arg, deparse_context *context,
Oid resulttype, int32 resulttypmod,
Node *parentNode)
{
StringInfo buf = context->buf;
/*
* Since parse_coerce.c doesn't immediately collapse application of
* length-coercion functions to constants, what we'll typically see in
* such cases is a Const with typmod -1 and a length-coercion function
* right above it. Avoid generating redundant output. However, beware of
* suppressing casts when the user actually wrote something like
* 'foo'::text::char(3).
*
* Note: it might seem that we are missing the possibility of needing to
* print a COLLATE clause for such a Const. However, a Const could only
* have nondefault collation in a post-constant-folding tree, in which the
* length coercion would have been folded too. See also the special
* handling of CollateExpr in coerce_to_target_type(): any collation
* marking will be above the coercion node, not below it.
*/
if (arg && IsA(arg, Const) &&
((Const *) arg)->consttype == resulttype &&
((Const *) arg)->consttypmod == -1)
{
/* Show the constant without normal ::typename decoration */
get_const_expr((Const *) arg, context, -1);
}
else
{
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, false, parentNode);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
appendStringInfo(buf, "::%s",
format_type_with_typemod(resulttype, resulttypmod));
}
/* ----------
* get_const_expr
*
* Make a string representation of a Const
*
* showtype can be -1 to never show "::typename" decoration, or +1 to always
* show it, or 0 to show it only if the constant wouldn't be assumed to be
* the right type by default.
*
* If the Const's collation isn't default for its type, show that too.
* We mustn't do this when showtype is -1 (since that means the caller will
* print "::typename", and we can't put a COLLATE clause in between). It's
* caller's responsibility that collation isn't missed in such cases.
* ----------
*/
static void
get_const_expr(Const *constval, deparse_context *context, int showtype)
{
StringInfo buf = context->buf;
Oid typoutput;
bool typIsVarlena;
char *extval;
bool needlabel = false;
if (constval->constisnull)
{
/*
* Always label the type of a NULL constant to prevent misdecisions
* about type when reparsing.
*/
appendStringInfoString(buf, "NULL");
if (showtype >= 0)
{
appendStringInfo(buf, "::%s",
format_type_with_typemod(constval->consttype,
constval->consttypmod));
get_const_collation(constval, context);
}
return;
}
getTypeOutputInfo(constval->consttype,
&typoutput, &typIsVarlena);
extval = OidOutputFunctionCall(typoutput, constval->constvalue);
switch (constval->consttype)
{
case INT4OID:
/*
* INT4 can be printed without any decoration, unless it is
* negative; in that case print it as '-nnn'::integer to ensure
* that the output will re-parse as a constant, not as a constant
* plus operator. In most cases we could get away with printing
* (-nnn) instead, because of the way that gram.y handles negative
* literals; but that doesn't work for INT_MIN, and it doesn't
* seem that much prettier anyway.
*/
if (extval[0] != '-')
appendStringInfoString(buf, extval);
else
{
appendStringInfo(buf, "'%s'", extval);
needlabel = true; /* we must attach a cast */
}
break;
case NUMERICOID:
/*
* NUMERIC can be printed without quotes if it looks like a float
* constant (not an integer, and not Infinity or NaN) and doesn't
* have a leading sign (for the same reason as for INT4).
*/
if (isdigit((unsigned char) extval[0]) &&
strcspn(extval, "eE.") != strlen(extval))
{
appendStringInfoString(buf, extval);
}
else
{
appendStringInfo(buf, "'%s'", extval);
needlabel = true; /* we must attach a cast */
}
break;
case BITOID:
case VARBITOID:
appendStringInfo(buf, "B'%s'", extval);
break;
case BOOLOID:
if (strcmp(extval, "t") == 0)
appendStringInfoString(buf, "true");
else
appendStringInfoString(buf, "false");
break;
default:
simple_quote_literal(buf, extval);
break;
}
pfree(extval);
if (showtype < 0)
return;
/*
* For showtype == 0, append ::typename unless the constant will be
* implicitly typed as the right type when it is read in.
*
* XXX this code has to be kept in sync with the behavior of the parser,
* especially make_const.
*/
switch (constval->consttype)
{
case BOOLOID:
case UNKNOWNOID:
/* These types can be left unlabeled */
needlabel = false;
break;
case INT4OID:
/* We determined above whether a label is needed */
break;
case NUMERICOID:
/*
* Float-looking constants will be typed as numeric, which we
* checked above; but if there's a nondefault typmod we need to
* show it.
*/
needlabel |= (constval->consttypmod >= 0);
break;
default:
needlabel = true;
break;
}
if (needlabel || showtype > 0)
appendStringInfo(buf, "::%s",
format_type_with_typemod(constval->consttype,
constval->consttypmod));
get_const_collation(constval, context);
}
/*
* helper for get_const_expr: append COLLATE if needed
*/
static void
get_const_collation(Const *constval, deparse_context *context)
{
StringInfo buf = context->buf;
if (OidIsValid(constval->constcollid))
{
Oid typcollation = get_typcollation(constval->consttype);
if (constval->constcollid != typcollation)
{
appendStringInfo(buf, " COLLATE %s",
generate_collation_name(constval->constcollid));
}
}
}
/*
* simple_quote_literal - Format a string as a SQL literal, append to buf
*/
static void
simple_quote_literal(StringInfo buf, const char *val)
{
const char *valptr;
/*
* We form the string literal according to the prevailing setting of
* standard_conforming_strings; we never use E''. User is responsible for
* making sure result is used correctly.
*/
appendStringInfoChar(buf, '\'');
for (valptr = val; *valptr; valptr++)
{
char ch = *valptr;
if (SQL_STR_DOUBLE(ch, !standard_conforming_strings))
appendStringInfoChar(buf, ch);
appendStringInfoChar(buf, ch);
}
appendStringInfoChar(buf, '\'');
}
/* ----------
* get_sublink_expr - Parse back a sublink
* ----------
*/
static void
get_sublink_expr(SubLink *sublink, deparse_context *context)
{
StringInfo buf = context->buf;
Query *query = (Query *) (sublink->subselect);
char *opname = NULL;
bool need_paren;
if (sublink->subLinkType == ARRAY_SUBLINK)
appendStringInfoString(buf, "ARRAY(");
else
appendStringInfoChar(buf, '(');
/*
* Note that we print the name of only the first operator, when there are
* multiple combining operators. This is an approximation that could go
* wrong in various scenarios (operators in different schemas, renamed
* operators, etc) but there is not a whole lot we can do about it, since
* the syntax allows only one operator to be shown.
*/
if (sublink->testexpr)
{
if (IsA(sublink->testexpr, OpExpr))
{
/* single combining operator */
OpExpr *opexpr = (OpExpr *) sublink->testexpr;
get_rule_expr(linitial(opexpr->args), context, true);
opname = generate_operator_name(opexpr->opno,
exprType(linitial(opexpr->args)),
exprType(lsecond(opexpr->args)));
}
else if (IsA(sublink->testexpr, BoolExpr))
{
/* multiple combining operators, = or <> cases */
char *sep;
ListCell *l;
appendStringInfoChar(buf, '(');
sep = "";
foreach(l, ((BoolExpr *) sublink->testexpr)->args)
{
OpExpr *opexpr = (OpExpr *) lfirst(l);
Assert(IsA(opexpr, OpExpr));
appendStringInfoString(buf, sep);
get_rule_expr(linitial(opexpr->args), context, true);
if (!opname)
opname = generate_operator_name(opexpr->opno,
exprType(linitial(opexpr->args)),
exprType(lsecond(opexpr->args)));
sep = ", ";
}
appendStringInfoChar(buf, ')');
}
else if (IsA(sublink->testexpr, RowCompareExpr))
{
/* multiple combining operators, < <= > >= cases */
RowCompareExpr *rcexpr = (RowCompareExpr *) sublink->testexpr;
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) rcexpr->largs, context, true);
opname = generate_operator_name(linitial_oid(rcexpr->opnos),
exprType(linitial(rcexpr->largs)),
exprType(linitial(rcexpr->rargs)));
appendStringInfoChar(buf, ')');
}
else
elog(ERROR, "unrecognized testexpr type: %d",
(int) nodeTag(sublink->testexpr));
}
need_paren = true;
switch (sublink->subLinkType)
{
case EXISTS_SUBLINK:
appendStringInfoString(buf, "EXISTS ");
break;
case ANY_SUBLINK:
if (strcmp(opname, "=") == 0) /* Represent = ANY as IN */
appendStringInfoString(buf, " IN ");
else
appendStringInfo(buf, " %s ANY ", opname);
break;
case ALL_SUBLINK:
appendStringInfo(buf, " %s ALL ", opname);
break;
case ROWCOMPARE_SUBLINK:
appendStringInfo(buf, " %s ", opname);
break;
case EXPR_SUBLINK:
case MULTIEXPR_SUBLINK:
case ARRAY_SUBLINK:
need_paren = false;
break;
case CTE_SUBLINK: /* shouldn't occur in a SubLink */
default:
elog(ERROR, "unrecognized sublink type: %d",
(int) sublink->subLinkType);
break;
}
if (need_paren)
appendStringInfoChar(buf, '(');
get_query_def(query, buf, context->namespaces, NULL,
context->prettyFlags, context->wrapColumn,
context->indentLevel);
if (need_paren)
appendStringInfoString(buf, "))");
else
appendStringInfoChar(buf, ')');
}
/* ----------
* get_from_clause - Parse back a FROM clause
*
* "prefix" is the keyword that denotes the start of the list of FROM
* elements. It is FROM when used to parse back SELECT and UPDATE, but
* is USING when parsing back DELETE.
* ----------
*/
static void
get_from_clause(Query *query, const char *prefix, deparse_context *context)
{
StringInfo buf = context->buf;
bool first = true;
ListCell *l;
/*
* We use the query's jointree as a guide to what to print. However, we
* must ignore auto-added RTEs that are marked not inFromCl. (These can
* only appear at the top level of the jointree, so it's sufficient to
* check here.) This check also ensures we ignore the rule pseudo-RTEs
* for NEW and OLD.
*/
foreach(l, query->jointree->fromlist)
{
Node *jtnode = (Node *) lfirst(l);
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
if (!rte->inFromCl)
continue;
}
if (first)
{
appendContextKeyword(context, prefix,
-PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
first = false;
get_from_clause_item(jtnode, query, context);
}
else
{
StringInfoData itembuf;
appendStringInfoString(buf, ", ");
/*
* Put the new FROM item's text into itembuf so we can decide
* after we've got it whether or not it needs to go on a new line.
*/
initStringInfo(&itembuf);
context->buf = &itembuf;
get_from_clause_item(jtnode, query, context);
/* Restore context's output buffer */
context->buf = buf;
/* Consider line-wrapping if enabled */
if (PRETTY_INDENT(context) && context->wrapColumn >= 0)
{
/* Does the new item start with a new line? */
if (itembuf.len > 0 && itembuf.data[0] == '\n')
{
/* If so, we shouldn't add anything */
/* instead, remove any trailing spaces currently in buf */
removeStringInfoSpaces(buf);
}
else
{
char *trailing_nl;
/* Locate the start of the current line in the buffer */
trailing_nl = strrchr(buf->data, '\n');
if (trailing_nl == NULL)
trailing_nl = buf->data;
else
trailing_nl++;
/*
* Add a newline, plus some indentation, if the new item
* would cause an overflow.
*/
if (strlen(trailing_nl) + itembuf.len > context->wrapColumn)
appendContextKeyword(context, "", -PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_VAR);
}
}
/* Add the new item */
appendStringInfoString(buf, itembuf.data);
/* clean up */
pfree(itembuf.data);
}
}
}
static void
get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
deparse_namespace *dpns = (deparse_namespace *) linitial(context->namespaces);
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
char *refname = get_rtable_name(varno, context);
deparse_columns *colinfo = deparse_columns_fetch(varno, dpns);
RangeTblFunction *rtfunc1 = NULL;
bool printalias;
if (rte->lateral)
appendStringInfoString(buf, "LATERAL ");
/* Print the FROM item proper */
switch (rte->rtekind)
{
case RTE_RELATION:
/* Normal relation RTE */
appendStringInfo(buf, "%s%s",
only_marker(rte),
generate_relation_name(rte->relid,
context->namespaces));
break;
case RTE_SUBQUERY:
/* Subquery RTE */
appendStringInfoChar(buf, '(');
get_query_def(rte->subquery, buf, context->namespaces, NULL,
context->prettyFlags, context->wrapColumn,
context->indentLevel);
appendStringInfoChar(buf, ')');
break;
case RTE_FUNCTION:
/* Function RTE */
rtfunc1 = (RangeTblFunction *) linitial(rte->functions);
/*
* Omit ROWS FROM() syntax for just one function, unless it
* has both a coldeflist and WITH ORDINALITY. If it has both,
* we must use ROWS FROM() syntax to avoid ambiguity about
* whether the coldeflist includes the ordinality column.
*/
if (list_length(rte->functions) == 1 &&
(rtfunc1->funccolnames == NIL || !rte->funcordinality))
{
get_rule_expr(rtfunc1->funcexpr, context, true);
/* we'll print the coldeflist below, if it has one */
}
else
{
bool all_unnest;
ListCell *lc;
/*
* If all the function calls in the list are to unnest,
* and none need a coldeflist, then collapse the list back
* down to UNNEST(args). (If we had more than one
* built-in unnest function, this would get more
* difficult.)
*
* XXX This is pretty ugly, since it makes not-terribly-
* future-proof assumptions about what the parser would do
* with the output; but the alternative is to emit our
* nonstandard ROWS FROM() notation for what might have
* been a perfectly spec-compliant multi-argument
* UNNEST().
*/
all_unnest = true;
foreach(lc, rte->functions)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
if (!IsA(rtfunc->funcexpr, FuncExpr) ||
((FuncExpr *) rtfunc->funcexpr)->funcid != F_ARRAY_UNNEST ||
rtfunc->funccolnames != NIL)
{
all_unnest = false;
break;
}
}
if (all_unnest)
{
List *allargs = NIL;
foreach(lc, rte->functions)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
List *args = ((FuncExpr *) rtfunc->funcexpr)->args;
allargs = list_concat(allargs, list_copy(args));
}
appendStringInfoString(buf, "UNNEST(");
get_rule_expr((Node *) allargs, context, true);
appendStringInfoChar(buf, ')');
}
else
{
int funcno = 0;
appendStringInfoString(buf, "ROWS FROM(");
foreach(lc, rte->functions)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
if (funcno > 0)
appendStringInfoString(buf, ", ");
get_rule_expr(rtfunc->funcexpr, context, true);
if (rtfunc->funccolnames != NIL)
{
/* Reconstruct the column definition list */
appendStringInfoString(buf, " AS ");
get_from_clause_coldeflist(rtfunc,
NULL,
context);
}
funcno++;
}
appendStringInfoChar(buf, ')');
}
/* prevent printing duplicate coldeflist below */
rtfunc1 = NULL;
}
if (rte->funcordinality)
appendStringInfoString(buf, " WITH ORDINALITY");
break;
case RTE_VALUES:
/* Values list RTE */
appendStringInfoChar(buf, '(');
get_values_def(rte->values_lists, context);
appendStringInfoChar(buf, ')');
break;
case RTE_CTE:
appendStringInfoString(buf, quote_identifier(rte->ctename));
break;
default:
elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind);
break;
}
/* Print the relation alias, if needed */
printalias = false;
if (rte->alias != NULL)
{
/* Always print alias if user provided one */
printalias = true;
}
else if (colinfo->printaliases)
{
/* Always print alias if we need to print column aliases */
printalias = true;
}
else if (rte->rtekind == RTE_RELATION)
{
/*
* No need to print alias if it's same as relation name (this
* would normally be the case, but not if set_rtable_names had to
* resolve a conflict).
*/
if (strcmp(refname, get_relation_name(rte->relid)) != 0)
printalias = true;
}
else if (rte->rtekind == RTE_FUNCTION)
{
/*
* For a function RTE, always print alias. This covers possible
* renaming of the function and/or instability of the
* FigureColname rules for things that aren't simple functions.
* Note we'd need to force it anyway for the columndef list case.
*/
printalias = true;
}
else if (rte->rtekind == RTE_VALUES)
{
/* Alias is syntactically required for VALUES */
printalias = true;
}
else if (rte->rtekind == RTE_CTE)
{
/*
* No need to print alias if it's same as CTE name (this would
* normally be the case, but not if set_rtable_names had to
* resolve a conflict).
*/
if (strcmp(refname, rte->ctename) != 0)
printalias = true;
}
if (printalias)
appendStringInfo(buf, " %s", quote_identifier(refname));
/* Print the column definitions or aliases, if needed */
if (rtfunc1 && rtfunc1->funccolnames != NIL)
{
/* Reconstruct the columndef list, which is also the aliases */
get_from_clause_coldeflist(rtfunc1, colinfo, context);
}
else
{
/* Else print column aliases as needed */
get_column_alias_list(colinfo, context);
}
/* Tablesample clause must go after any alias */
if (rte->rtekind == RTE_RELATION && rte->tablesample)
get_tablesample_def(rte->tablesample, context);
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
deparse_columns *colinfo = deparse_columns_fetch(j->rtindex, dpns);
bool need_paren_on_right;
need_paren_on_right = PRETTY_PAREN(context) &&
!IsA(j->rarg, RangeTblRef) &&
!(IsA(j->rarg, JoinExpr) &&((JoinExpr *) j->rarg)->alias != NULL);
if (!PRETTY_PAREN(context) || j->alias != NULL)
appendStringInfoChar(buf, '(');
get_from_clause_item(j->larg, query, context);
switch (j->jointype)
{
case JOIN_INNER:
if (j->quals)
appendContextKeyword(context, " JOIN ",
-PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_JOIN);
else
appendContextKeyword(context, " CROSS JOIN ",
-PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_JOIN);
break;
case JOIN_LEFT:
appendContextKeyword(context, " LEFT JOIN ",
-PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_JOIN);
break;
case JOIN_FULL:
appendContextKeyword(context, " FULL JOIN ",
-PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_JOIN);
break;
case JOIN_RIGHT:
appendContextKeyword(context, " RIGHT JOIN ",
-PRETTYINDENT_STD,
PRETTYINDENT_STD,
PRETTYINDENT_JOIN);
break;
default:
elog(ERROR, "unrecognized join type: %d",
(int) j->jointype);
}
if (need_paren_on_right)
appendStringInfoChar(buf, '(');
get_from_clause_item(j->rarg, query, context);
if (need_paren_on_right)
appendStringInfoChar(buf, ')');
if (j->usingClause)
{
ListCell *lc;
bool first = true;
appendStringInfoString(buf, " USING (");
/* Use the assigned names, not what's in usingClause */
foreach(lc, colinfo->usingNames)
{
char *colname = (char *) lfirst(lc);
if (first)
first = false;
else
appendStringInfoString(buf, ", ");
appendStringInfoString(buf, quote_identifier(colname));
}
appendStringInfoChar(buf, ')');
}
else if (j->quals)
{
appendStringInfoString(buf, " ON ");
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr(j->quals, context, false);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
if (!PRETTY_PAREN(context) || j->alias != NULL)
appendStringInfoChar(buf, ')');
/* Yes, it's correct to put alias after the right paren ... */
if (j->alias != NULL)
{
appendStringInfo(buf, " %s",
quote_identifier(j->alias->aliasname));
get_column_alias_list(colinfo, context);
}
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
}
/*
* get_column_alias_list - print column alias list for an RTE
*
* Caller must already have printed the relation's alias name.
*/
static void
get_column_alias_list(deparse_columns *colinfo, deparse_context *context)
{
StringInfo buf = context->buf;
int i;
bool first = true;
/* Don't print aliases if not needed */
if (!colinfo->printaliases)
return;
for (i = 0; i < colinfo->num_new_cols; i++)
{
char *colname = colinfo->new_colnames[i];
if (first)
{
appendStringInfoChar(buf, '(');
first = false;
}
else
appendStringInfoString(buf, ", ");
appendStringInfoString(buf, quote_identifier(colname));
}
if (!first)
appendStringInfoChar(buf, ')');
}
/*
* get_from_clause_coldeflist - reproduce FROM clause coldeflist
*
* When printing a top-level coldeflist (which is syntactically also the
* relation's column alias list), use column names from colinfo. But when
* printing a coldeflist embedded inside ROWS FROM(), we prefer to use the
* original coldeflist's names, which are available in rtfunc->funccolnames.
* Pass NULL for colinfo to select the latter behavior.
*
* The coldeflist is appended immediately (no space) to buf. Caller is
* responsible for ensuring that an alias or AS is present before it.
*/
static void
get_from_clause_coldeflist(RangeTblFunction *rtfunc,
deparse_columns *colinfo,
deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *l1;
ListCell *l2;
ListCell *l3;
ListCell *l4;
int i;
appendStringInfoChar(buf, '(');
/* there's no forfour(), so must chase one list the hard way */
i = 0;
l4 = list_head(rtfunc->funccolnames);
forthree(l1, rtfunc->funccoltypes,
l2, rtfunc->funccoltypmods,
l3, rtfunc->funccolcollations)
{
Oid atttypid = lfirst_oid(l1);
int32 atttypmod = lfirst_int(l2);
Oid attcollation = lfirst_oid(l3);
char *attname;
if (colinfo)
attname = colinfo->colnames[i];
else
attname = strVal(lfirst(l4));
Assert(attname); /* shouldn't be any dropped columns here */
if (i > 0)
appendStringInfoString(buf, ", ");
appendStringInfo(buf, "%s %s",
quote_identifier(attname),
format_type_with_typemod(atttypid, atttypmod));
if (OidIsValid(attcollation) &&
attcollation != get_typcollation(atttypid))
appendStringInfo(buf, " COLLATE %s",
generate_collation_name(attcollation));
l4 = lnext(l4);
i++;
}
appendStringInfoChar(buf, ')');
}
/*
* get_tablesample_def - print a TableSampleClause
*/
static void
get_tablesample_def(TableSampleClause *tablesample, deparse_context *context)
{
StringInfo buf = context->buf;
Oid argtypes[1];
int nargs;
ListCell *l;
/*
* We should qualify the handler's function name if it wouldn't be
* resolved by lookup in the current search path.
*/
argtypes[0] = INTERNALOID;
appendStringInfo(buf, " TABLESAMPLE %s (",
generate_function_name(tablesample->tsmhandler, 1,
NIL, argtypes,
false, NULL, EXPR_KIND_NONE));
nargs = 0;
foreach(l, tablesample->args)
{
if (nargs++ > 0)
appendStringInfoString(buf, ", ");
get_rule_expr((Node *) lfirst(l), context, false);
}
appendStringInfoChar(buf, ')');
if (tablesample->repeatable != NULL)
{
appendStringInfoString(buf, " REPEATABLE (");
get_rule_expr((Node *) tablesample->repeatable, context, false);
appendStringInfoChar(buf, ')');
}
}
/*
* get_opclass_name - fetch name of an index operator class
*
* The opclass name is appended (after a space) to buf.
*
* Output is suppressed if the opclass is the default for the given
* actual_datatype. (If you don't want this behavior, just pass
* InvalidOid for actual_datatype.)
*/
static void
get_opclass_name(Oid opclass, Oid actual_datatype,
StringInfo buf)
{
HeapTuple ht_opc;
Form_pg_opclass opcrec;
char *opcname;
char *nspname;
ht_opc = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclass));
if (!HeapTupleIsValid(ht_opc))
elog(ERROR, "cache lookup failed for opclass %u", opclass);
opcrec = (Form_pg_opclass) GETSTRUCT(ht_opc);
if (!OidIsValid(actual_datatype) ||
GetDefaultOpClass(actual_datatype, opcrec->opcmethod) != opclass)
{
/* Okay, we need the opclass name. Do we need to qualify it? */
opcname = NameStr(opcrec->opcname);
if (OpclassIsVisible(opclass))
appendStringInfo(buf, " %s", quote_identifier(opcname));
else
{
nspname = get_namespace_name(opcrec->opcnamespace);
appendStringInfo(buf, " %s.%s",
quote_identifier(nspname),
quote_identifier(opcname));
}
}
ReleaseSysCache(ht_opc);
}
/*
* processIndirection - take care of array and subfield assignment
*
* We strip any top-level FieldStore or assignment ArrayRef nodes that
* appear in the input, and return the subexpression that's to be assigned.
* If printit is true, we also print out the appropriate decoration for the
* base column name (that the caller just printed).
*/
static Node *
processIndirection(Node *node, deparse_context *context, bool printit)
{
StringInfo buf = context->buf;
for (;;)
{
if (node == NULL)
break;
if (IsA(node, FieldStore))
{
FieldStore *fstore = (FieldStore *) node;
Oid typrelid;
char *fieldname;
/* lookup tuple type */
typrelid = get_typ_typrelid(fstore->resulttype);
if (!OidIsValid(typrelid))
elog(ERROR, "argument type %s of FieldStore is not a tuple type",
format_type_be(fstore->resulttype));
/*
* Print the field name. There should only be one target field in
* stored rules. There could be more than that in executable
* target lists, but this function cannot be used for that case.
*/
Assert(list_length(fstore->fieldnums) == 1);
fieldname = get_relid_attribute_name(typrelid,
linitial_int(fstore->fieldnums));
if (printit)
appendStringInfo(buf, ".%s", quote_identifier(fieldname));
/*
* We ignore arg since it should be an uninteresting reference to
* the target column or subcolumn.
*/
node = (Node *) linitial(fstore->newvals);
}
else if (IsA(node, ArrayRef))
{
ArrayRef *aref = (ArrayRef *) node;
if (aref->refassgnexpr == NULL)
break;
if (printit)
printSubscripts(aref, context);
/*
* We ignore refexpr since it should be an uninteresting reference
* to the target column or subcolumn.
*/
node = (Node *) aref->refassgnexpr;
}
else
break;
}
return node;
}
static void
printSubscripts(ArrayRef *aref, deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *lowlist_item;
ListCell *uplist_item;
lowlist_item = list_head(aref->reflowerindexpr); /* could be NULL */
foreach(uplist_item, aref->refupperindexpr)
{
appendStringInfoChar(buf, '[');
if (lowlist_item)
{
/* If subexpression is NULL, get_rule_expr prints nothing */
get_rule_expr((Node *) lfirst(lowlist_item), context, false);
appendStringInfoChar(buf, ':');
lowlist_item = lnext(lowlist_item);
}
/* If subexpression is NULL, get_rule_expr prints nothing */
get_rule_expr((Node *) lfirst(uplist_item), context, false);
appendStringInfoChar(buf, ']');
}
}
/*
* quote_identifier - Quote an identifier only if needed
*
* When quotes are needed, we palloc the required space; slightly
* space-wasteful but well worth it for notational simplicity.
*/
const char *
quote_identifier(const char *ident)
{
/*
* Can avoid quoting if ident starts with a lowercase letter or underscore
* and contains only lowercase letters, digits, and underscores, *and* is
* not any SQL keyword. Otherwise, supply quotes.
*/
int nquotes = 0;
bool safe;
const char *ptr;
char *result;
char *optr;
/*
* would like to use <ctype.h> macros here, but they might yield unwanted
* locale-specific results...
*/
safe = ((ident[0] >= 'a' && ident[0] <= 'z') || ident[0] == '_');
for (ptr = ident; *ptr; ptr++)
{
char ch = *ptr;
if ((ch >= 'a' && ch <= 'z') ||
(ch >= '0' && ch <= '9') ||
(ch == '_'))
{
/* okay */
}
else
{
safe = false;
if (ch == '"')
nquotes++;
}
}
if (quote_all_identifiers)
safe = false;
if (safe)
{
/*
* Check for keyword. We quote keywords except for unreserved ones.
* (In some cases we could avoid quoting a col_name or type_func_name
* keyword, but it seems much harder than it's worth to tell that.)
*
* Note: ScanKeywordLookup() does case-insensitive comparison, but
* that's fine, since we already know we have all-lower-case.
*/
const ScanKeyword *keyword = ScanKeywordLookup(ident,
ScanKeywords,
NumScanKeywords);
if (keyword != NULL && keyword->category != UNRESERVED_KEYWORD)
safe = false;
}
if (safe)
return ident; /* no change needed */
result = (char *) palloc(strlen(ident) + nquotes + 2 + 1);
optr = result;
*optr++ = '"';
for (ptr = ident; *ptr; ptr++)
{
char ch = *ptr;
if (ch == '"')
*optr++ = '"';
*optr++ = ch;
}
*optr++ = '"';
*optr = '\0';
return result;
}
/*
* quote_qualified_identifier - Quote a possibly-qualified identifier
*
* Return a name of the form qualifier.ident, or just ident if qualifier
* is NULL, quoting each component if necessary. The result is palloc'd.
*/
char *
quote_qualified_identifier(const char *qualifier,
const char *ident)
{
StringInfoData buf;
initStringInfo(&buf);
if (qualifier)
appendStringInfo(&buf, "%s.", quote_identifier(qualifier));
appendStringInfoString(&buf, quote_identifier(ident));
return buf.data;
}
/*
* get_relation_name
* Get the unqualified name of a relation specified by OID
*
* This differs from the underlying get_rel_name() function in that it will
* throw error instead of silently returning NULL if the OID is bad.
*/
static char *
get_relation_name(Oid relid)
{
char *relname = get_rel_name(relid);
if (!relname)
elog(ERROR, "cache lookup failed for relation %u", relid);
return relname;
}
/*
* generate_relation_name
* Compute the name to display for a relation specified by OID
*
* The result includes all necessary quoting and schema-prefixing.
*
* If namespaces isn't NIL, it must be a list of deparse_namespace nodes.
* We will forcibly qualify the relation name if it equals any CTE name
* visible in the namespace list.
*/
static char *
generate_relation_name(Oid relid, List *namespaces)
{
HeapTuple tp;
Form_pg_class reltup;
bool need_qual;
ListCell *nslist;
char *relname;
char *nspname;
char *result;
tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for relation %u", relid);
reltup = (Form_pg_class) GETSTRUCT(tp);
relname = NameStr(reltup->relname);
/* Check for conflicting CTE name */
need_qual = false;
foreach(nslist, namespaces)
{
deparse_namespace *dpns = (deparse_namespace *) lfirst(nslist);
ListCell *ctlist;
foreach(ctlist, dpns->ctes)
{
CommonTableExpr *cte = (CommonTableExpr *) lfirst(ctlist);
if (strcmp(cte->ctename, relname) == 0)
{
need_qual = true;
break;
}
}
if (need_qual)
break;
}
/* Otherwise, qualify the name if not visible in search path */
if (!need_qual)
need_qual = !RelationIsVisible(relid);
if (need_qual)
nspname = get_namespace_name(reltup->relnamespace);
else
nspname = NULL;
result = quote_qualified_identifier(nspname, relname);
ReleaseSysCache(tp);
return result;
}
/*
* generate_qualified_relation_name
* Compute the name to display for a relation specified by OID
*
* As above, but unconditionally schema-qualify the name.
*/
static char *
generate_qualified_relation_name(Oid relid)
{
HeapTuple tp;
Form_pg_class reltup;
char *relname;
char *nspname;
char *result;
tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for relation %u", relid);
reltup = (Form_pg_class) GETSTRUCT(tp);
relname = NameStr(reltup->relname);
nspname = get_namespace_name(reltup->relnamespace);
if (!nspname)
elog(ERROR, "cache lookup failed for namespace %u",
reltup->relnamespace);
result = quote_qualified_identifier(nspname, relname);
ReleaseSysCache(tp);
return result;
}
/*
* generate_function_name
* Compute the name to display for a function specified by OID,
* given that it is being called with the specified actual arg names and
* types. (Those matter because of ambiguous-function resolution rules.)
*
* If we're dealing with a potentially variadic function (in practice, this
* means a FuncExpr or Aggref, not some other way of calling a function), then
* has_variadic must specify whether variadic arguments have been merged,
* and *use_variadic_p will be set to indicate whether to print VARIADIC in
* the output. For non-FuncExpr cases, has_variadic should be FALSE and
* use_variadic_p can be NULL.
*
* The result includes all necessary quoting and schema-prefixing.
*/
static char *
generate_function_name(Oid funcid, int nargs, List *argnames, Oid *argtypes,
bool has_variadic, bool *use_variadic_p,
ParseExprKind special_exprkind)
{
char *result;
HeapTuple proctup;
Form_pg_proc procform;
char *proname;
bool use_variadic;
char *nspname;
FuncDetailCode p_result;
Oid p_funcid;
Oid p_rettype;
bool p_retset;
int p_nvargs;
Oid p_vatype;
Oid *p_true_typeids;
bool force_qualify = false;
proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
procform = (Form_pg_proc) GETSTRUCT(proctup);
proname = NameStr(procform->proname);
/*
* Due to parser hacks to avoid needing to reserve CUBE, we need to force
* qualification in some special cases.
*/
if (special_exprkind == EXPR_KIND_GROUP_BY)
{
if (strcmp(proname, "cube") == 0 || strcmp(proname, "rollup") == 0)
force_qualify = true;
}
/*
* Determine whether VARIADIC should be printed. We must do this first
* since it affects the lookup rules in func_get_detail().
*
* Currently, we always print VARIADIC if the function has a merged
* variadic-array argument. Note that this is always the case for
* functions taking a VARIADIC argument type other than VARIADIC ANY.
*
* In principle, if VARIADIC wasn't originally specified and the array
* actual argument is deconstructable, we could print the array elements
* separately and not print VARIADIC, thus more nearly reproducing the
* original input. For the moment that seems like too much complication
* for the benefit, and anyway we do not know whether VARIADIC was
* originally specified if it's a non-ANY type.
*/
if (use_variadic_p)
{
/* Parser should not have set funcvariadic unless fn is variadic */
Assert(!has_variadic || OidIsValid(procform->provariadic));
use_variadic = has_variadic;
*use_variadic_p = use_variadic;
}
else
{
Assert(!has_variadic);
use_variadic = false;
}
/*
* The idea here is to schema-qualify only if the parser would fail to
* resolve the correct function given the unqualified func name with the
* specified argtypes and VARIADIC flag. But if we already decided to
* force qualification, then we can skip the lookup and pretend we didn't
* find it.
*/
if (!force_qualify)
p_result = func_get_detail(list_make1(makeString(proname)),
NIL, argnames, nargs, argtypes,
!use_variadic, true,
&p_funcid, &p_rettype,
&p_retset, &p_nvargs, &p_vatype,
&p_true_typeids, NULL);
else
{
p_result = FUNCDETAIL_NOTFOUND;
p_funcid = InvalidOid;
}
if ((p_result == FUNCDETAIL_NORMAL ||
p_result == FUNCDETAIL_AGGREGATE ||
p_result == FUNCDETAIL_WINDOWFUNC) &&
p_funcid == funcid)
nspname = NULL;
else
nspname = get_namespace_name(procform->pronamespace);
result = quote_qualified_identifier(nspname, proname);
ReleaseSysCache(proctup);
return result;
}
/*
* generate_operator_name
* Compute the name to display for an operator specified by OID,
* given that it is being called with the specified actual arg types.
* (Arg types matter because of ambiguous-operator resolution rules.
* Pass InvalidOid for unused arg of a unary operator.)
*
* The result includes all necessary quoting and schema-prefixing,
* plus the OPERATOR() decoration needed to use a qualified operator name
* in an expression.
*/
static char *
generate_operator_name(Oid operid, Oid arg1, Oid arg2)
{
StringInfoData buf;
HeapTuple opertup;
Form_pg_operator operform;
char *oprname;
char *nspname;
Operator p_result;
initStringInfo(&buf);
opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(operid));
if (!HeapTupleIsValid(opertup))
elog(ERROR, "cache lookup failed for operator %u", operid);
operform = (Form_pg_operator) GETSTRUCT(opertup);
oprname = NameStr(operform->oprname);
/*
* The idea here is to schema-qualify only if the parser would fail to
* resolve the correct operator given the unqualified op name with the
* specified argtypes.
*/
switch (operform->oprkind)
{
case 'b':
p_result = oper(NULL, list_make1(makeString(oprname)), arg1, arg2,
true, -1);
break;
case 'l':
p_result = left_oper(NULL, list_make1(makeString(oprname)), arg2,
true, -1);
break;
case 'r':
p_result = right_oper(NULL, list_make1(makeString(oprname)), arg1,
true, -1);
break;
default:
elog(ERROR, "unrecognized oprkind: %d", operform->oprkind);
p_result = NULL; /* keep compiler quiet */
break;
}
if (p_result != NULL && oprid(p_result) == operid)
nspname = NULL;
else
{
nspname = get_namespace_name(operform->oprnamespace);
appendStringInfo(&buf, "OPERATOR(%s.", quote_identifier(nspname));
}
appendStringInfoString(&buf, oprname);
if (nspname)
appendStringInfoChar(&buf, ')');
if (p_result != NULL)
ReleaseSysCache(p_result);
ReleaseSysCache(opertup);
return buf.data;
}
/*
* generate_collation_name
* Compute the name to display for a collation specified by OID
*
* The result includes all necessary quoting and schema-prefixing.
*/
char *
generate_collation_name(Oid collid)
{
HeapTuple tp;
Form_pg_collation colltup;
char *collname;
char *nspname;
char *result;
tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for collation %u", collid);
colltup = (Form_pg_collation) GETSTRUCT(tp);
collname = NameStr(colltup->collname);
if (!CollationIsVisible(collid))
nspname = get_namespace_name(colltup->collnamespace);
else
nspname = NULL;
result = quote_qualified_identifier(nspname, collname);
ReleaseSysCache(tp);
return result;
}
/*
* Given a C string, produce a TEXT datum.
*
* We assume that the input was palloc'd and may be freed.
*/
static text *
string_to_text(char *str)
{
text *result;
result = cstring_to_text(str);
pfree(str);
return result;
}
/*
* Generate a C string representing a relation's reloptions, or NULL if none.
*/
static char *
flatten_reloptions(Oid relid)
{
char *result = NULL;
HeapTuple tuple;
Datum reloptions;
bool isnull;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
reloptions = SysCacheGetAttr(RELOID, tuple,
Anum_pg_class_reloptions, &isnull);
if (!isnull)
{
StringInfoData buf;
Datum *options;
int noptions;
int i;
initStringInfo(&buf);
deconstruct_array(DatumGetArrayTypeP(reloptions),
TEXTOID, -1, false, 'i',
&options, NULL, &noptions);
for (i = 0; i < noptions; i++)
{
char *option = TextDatumGetCString(options[i]);
char *name;
char *separator;
char *value;
/*
* Each array element should have the form name=value. If the "="
* is missing for some reason, treat it like an empty value.
*/
name = option;
separator = strchr(option, '=');
if (separator)
{
*separator = '\0';
value = separator + 1;
}
else
value = "";
if (i > 0)
appendStringInfoString(&buf, ", ");
appendStringInfo(&buf, "%s=", quote_identifier(name));
/*
* In general we need to quote the value; but to avoid unnecessary
* clutter, do not quote if it is an identifier that would not
* need quoting. (We could also allow numbers, but that is a bit
* trickier than it looks --- for example, are leading zeroes
* significant? We don't want to assume very much here about what
* custom reloptions might mean.)
*/
if (quote_identifier(value) == value)
appendStringInfoString(&buf, value);
else
simple_quote_literal(&buf, value);
pfree(option);
}
result = buf.data;
}
ReleaseSysCache(tuple);
return result;
}
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