database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-04-22 23:02:54 +03:00
Code
postgres/src/backend/utils/adt/ri_triggers.c
Tom Lane e8c9fd5fdf Allow ON UPDATE/DELETE SET DEFAULT plans to be cached. 
Once upon a time, somebody was worried that cached RI plans wouldn't get
remade with new default values after ALTER TABLE ... SET DEFAULT, so they
didn't allow caching of plans for ON UPDATE/DELETE SET DEFAULT actions.
That time is long gone, though (and even at the time I doubt this was the
greatest hazard posed by ALTER TABLE...).  So allow these triggers to cache
their plans just like the others.

The cache_plan argument to ri_PlanCheck is now vestigial, since there
are no callers that don't pass "true"; but I left it alone in case there
is any future need for it.
2012-06-18 19:37:23 -04:00

3895 lines
104 KiB
C
Raw Blame History

/* ----------
* ri_triggers.c
*
* Generic trigger procedures for referential integrity constraint
* checks.
*
* Note about memory management: the private hashtables kept here live
* across query and transaction boundaries, in fact they live as long as
* the backend does. This works because the hashtable structures
* themselves are allocated by dynahash.c in its permanent DynaHashCxt,
* and the SPI plans they point to are saved using SPI_keepplan().
* There is not currently any provision for throwing away a no-longer-needed
* plan --- consider improving this someday.
*
*
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
*
* src/backend/utils/adt/ri_triggers.c
*
* ----------
*/
/* ----------
* Internal TODO:
*
* Add MATCH PARTIAL logic.
* ----------
*/
#include "postgres.h"
#include "access/xact.h"
#include "access/sysattr.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/spi.h"
#include "parser/parse_coerce.h"
#include "parser/parse_relation.h"
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
/* ----------
* Local definitions
* ----------
*/
#define RI_MAX_NUMKEYS INDEX_MAX_KEYS
#define RI_INIT_QUERYHASHSIZE 128
#define RI_KEYS_ALL_NULL 0
#define RI_KEYS_SOME_NULL 1
#define RI_KEYS_NONE_NULL 2
/* RI query type codes */
/* these queries are executed against the PK (referenced) table: */
#define RI_PLAN_CHECK_LOOKUPPK 1
#define RI_PLAN_CHECK_LOOKUPPK_FROM_PK 2
#define RI_PLAN_LAST_ON_PK RI_PLAN_CHECK_LOOKUPPK_FROM_PK
/* these queries are executed against the FK (referencing) table: */
#define RI_PLAN_CASCADE_DEL_DODELETE 3
#define RI_PLAN_CASCADE_UPD_DOUPDATE 4
#define RI_PLAN_NOACTION_DEL_CHECKREF 5
#define RI_PLAN_NOACTION_UPD_CHECKREF 6
#define RI_PLAN_RESTRICT_DEL_CHECKREF 7
#define RI_PLAN_RESTRICT_UPD_CHECKREF 8
#define RI_PLAN_SETNULL_DEL_DOUPDATE 9
#define RI_PLAN_SETNULL_UPD_DOUPDATE 10
#define RI_PLAN_SETDEFAULT_DEL_DOUPDATE 11
#define RI_PLAN_SETDEFAULT_UPD_DOUPDATE 12
#define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)
#define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)
#define RIAttName(rel, attnum) NameStr(*attnumAttName(rel, attnum))
#define RIAttType(rel, attnum) attnumTypeId(rel, attnum)
#define RIAttCollation(rel, attnum) attnumCollationId(rel, attnum)
#define RI_TRIGTYPE_INSERT 1
#define RI_TRIGTYPE_UPDATE 2
#define RI_TRIGTYPE_INUP 3
#define RI_TRIGTYPE_DELETE 4
/* ----------
* RI_ConstraintInfo
*
* Information extracted from an FK pg_constraint entry.
* ----------
*/
typedef struct RI_ConstraintInfo
{
Oid constraint_id; /* OID of pg_constraint entry */
NameData conname; /* name of the FK constraint */
Oid pk_relid; /* referenced relation */
Oid fk_relid; /* referencing relation */
char confupdtype; /* foreign key's ON UPDATE action */
char confdeltype; /* foreign key's ON DELETE action */
char confmatchtype; /* foreign key's match type */
int nkeys; /* number of key columns */
int16 pk_attnums[RI_MAX_NUMKEYS]; /* attnums of referenced cols */
int16 fk_attnums[RI_MAX_NUMKEYS]; /* attnums of referencing cols */
Oid pf_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK =
* FK) */
Oid pp_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (PK =
* PK) */
Oid ff_eq_oprs[RI_MAX_NUMKEYS]; /* equality operators (FK =
* FK) */
} RI_ConstraintInfo;
/* ----------
* RI_QueryKey
*
* The key identifying a prepared SPI plan in our query hashtable
* ----------
*/
typedef struct RI_QueryKey
{
Oid constr_id; /* OID of pg_constraint entry */
int32 constr_queryno; /* query type ID, see RI_PLAN_XXX above */
} RI_QueryKey;
/* ----------
* RI_QueryHashEntry
* ----------
*/
typedef struct RI_QueryHashEntry
{
RI_QueryKey key;
SPIPlanPtr plan;
} RI_QueryHashEntry;
/* ----------
* RI_CompareKey
*
* The key identifying an entry showing how to compare two values
* ----------
*/
typedef struct RI_CompareKey
{
Oid eq_opr; /* the equality operator to apply */
Oid typeid; /* the data type to apply it to */
} RI_CompareKey;
/* ----------
* RI_CompareHashEntry
* ----------
*/
typedef struct RI_CompareHashEntry
{
RI_CompareKey key;
bool valid; /* successfully initialized? */
FmgrInfo eq_opr_finfo; /* call info for equality fn */
FmgrInfo cast_func_finfo; /* in case we must coerce input */
} RI_CompareHashEntry;
/* ----------
* Local data
* ----------
*/
static HTAB *ri_query_cache = NULL;
static HTAB *ri_compare_cache = NULL;
/* ----------
* Local function prototypes
* ----------
*/
static void quoteOneName(char *buffer, const char *name);
static void quoteRelationName(char *buffer, Relation rel);
static void ri_GenerateQual(StringInfo buf,
const char *sep,
const char *leftop, Oid leftoptype,
Oid opoid,
const char *rightop, Oid rightoptype);
static void ri_add_cast_to(StringInfo buf, Oid typid);
static void ri_GenerateQualCollation(StringInfo buf, Oid collation);
static int ri_NullCheck(HeapTuple tup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk);
static void ri_BuildQueryKey(RI_QueryKey *key,
const RI_ConstraintInfo *riinfo,
int32 constr_queryno);
static bool ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk);
static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
Datum oldvalue, Datum newvalue);
static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
HeapTuple old_row,
const RI_ConstraintInfo *riinfo);
static void ri_InitHashTables(void);
static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
static void ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan);
static RI_CompareHashEntry *ri_HashCompareOp(Oid eq_opr, Oid typeid);
static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
int tgkind);
static void ri_FetchConstraintInfo(RI_ConstraintInfo *riinfo,
Trigger *trigger, Relation trig_rel, bool rel_is_pk);
static SPIPlanPtr ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
bool cache_plan);
static bool ri_PerformCheck(const RI_ConstraintInfo *riinfo,
RI_QueryKey *qkey, SPIPlanPtr qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows, int expect_OK);
static void ri_ExtractValues(Relation rel, HeapTuple tup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk,
Datum *vals, char *nulls);
static void ri_ReportViolation(const RI_ConstraintInfo *riinfo,
Relation pk_rel, Relation fk_rel,
HeapTuple violator, TupleDesc tupdesc,
int queryno, bool spi_err);
/* ----------
* RI_FKey_check -
*
* Check foreign key existence (combined for INSERT and UPDATE).
* ----------
*/
static Datum
RI_FKey_check(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
Buffer new_row_buf;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_check", RI_TRIGTYPE_INUP);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, false);
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
new_row = trigdata->tg_newtuple;
new_row_buf = trigdata->tg_newtuplebuf;
}
else
{
new_row = trigdata->tg_trigtuple;
new_row_buf = trigdata->tg_trigtuplebuf;
}
/*
* We should not even consider checking the row if it is no longer valid,
* since it was either deleted (so the deferred check should be skipped)
* or updated (in which case only the latest version of the row should be
* checked). Test its liveness according to SnapshotSelf.
*
* NOTE: The normal coding rule is that one must acquire the buffer
* content lock to call HeapTupleSatisfiesVisibility. We can skip that
* here because we know that AfterTriggerExecute just fetched the tuple
* successfully, so there cannot be a VACUUM compaction in progress on the
* page (either heap_fetch would have waited for the VACUUM, or the
* VACUUM's LockBufferForCleanup would be waiting for us to drop pin). And
* since this is a row inserted by our open transaction, no one else can
* be entitled to change its xmin/xmax.
*/
Assert(new_row_buf != InvalidBuffer);
if (!HeapTupleSatisfiesVisibility(new_row, SnapshotSelf, new_row_buf))
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables.
*
* pk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR SHARE will get on it.
*/
fk_rel = trigdata->tg_relation;
pk_rel = heap_open(riinfo.pk_relid, RowShareLock);
/* ----------
* SQL:2008 4.17.3 <Table constraints>
* If Rf and Rt are empty (no columns to compare given)
* constraint is true if 0 < (SELECT COUNT(*) FROM T)
*
* Note: The special case that no columns are given cannot
* occur at present in Postgres (and is disallowed by the
* standard too); it's just there for future enhancements.
* ----------
*/
if (riinfo.nkeys == 0)
{
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_CHECK_LOOKUPPK);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100];
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
/* ---------
* The query string built is
* SELECT 1 FROM ONLY <pktable>
* ----------
*/
quoteRelationName(pkrelname, pk_rel);
snprintf(querystr, sizeof(querystr),
"SELECT 1 FROM ONLY %s x FOR SHARE OF x",
pkrelname);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, 0, NULL,
&qkey, fk_rel, pk_rel, true);
}
/*
* Execute the plan
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
NULL, NULL,
false,
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
if (riinfo.confmatchtype == FKCONSTR_MATCH_PARTIAL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
switch (ri_NullCheck(new_row, &riinfo, false))
{
case RI_KEYS_ALL_NULL:
/*
* No further check needed - an all-NULL key passes every type of
* foreign key constraint.
*/
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_KEYS_SOME_NULL:
/*
* This is the only case that differs between the three kinds of
* MATCH.
*/
switch (riinfo.confmatchtype)
{
case FKCONSTR_MATCH_FULL:
/*
* Not allowed - MATCH FULL says either all or none of the
* attributes can be NULLs
*/
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(trigdata->tg_relation),
NameStr(riinfo.conname)),
errdetail("MATCH FULL does not allow mixing of null and nonnull key values.")));
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
case FKCONSTR_MATCH_SIMPLE:
/*
* MATCH SIMPLE - if ANY column is null, the key passes
* the constraint.
*/
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
case FKCONSTR_MATCH_PARTIAL:
/*
* MATCH PARTIAL - all non-null columns must match. (not
* implemented, can be done by modifying the query below
* to only include non-null columns, or by writing a
* special version here)
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below for all three kinds
* of MATCH.
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the real check
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_CHECK_LOOKUPPK);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <pktable> WHERE pkatt1 = $1 [AND ...] FOR SHARE
* The type id's for the $ parameters are those of the
* corresponding FK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(pkrelname, pk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x", pkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(pk_rel, riinfo.pk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
attname, pk_type,
riinfo.pf_eq_oprs[i],
paramname, fk_type);
querysep = "AND";
queryoids[i] = fk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* Now check that foreign key exists in PK table
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
NULL, new_row,
false,
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_check_ins -
*
* Check foreign key existence at insert event on FK table.
* ----------
*/
Datum
RI_FKey_check_ins(PG_FUNCTION_ARGS)
{
return RI_FKey_check(fcinfo);
}
/* ----------
* RI_FKey_check_upd -
*
* Check foreign key existence at update event on FK table.
* ----------
*/
Datum
RI_FKey_check_upd(PG_FUNCTION_ARGS)
{
return RI_FKey_check(fcinfo);
}
/* ----------
* ri_Check_Pk_Match
*
* Check for matching value of old pk row in current state for
* noaction triggers. Returns false if no row was found and a fk row
* could potentially be referencing this row, true otherwise.
* ----------
*/
static bool
ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
HeapTuple old_row,
const RI_ConstraintInfo *riinfo)
{
SPIPlanPtr qplan;
RI_QueryKey qkey;
int i;
bool result;
switch (ri_NullCheck(old_row, riinfo, true))
{
case RI_KEYS_ALL_NULL:
/*
* No check - nothing could have been referencing this row anyway.
*/
return true;
case RI_KEYS_SOME_NULL:
/*
* This is the only case that differs between the three kinds of
* MATCH.
*/
switch (riinfo->confmatchtype)
{
case FKCONSTR_MATCH_FULL:
case FKCONSTR_MATCH_SIMPLE:
/*
* MATCH SIMPLE/FULL - if ANY column is null, nothing
* could have been referencing this row.
*/
return true;
case FKCONSTR_MATCH_PARTIAL:
/*
* MATCH PARTIAL - all non-null columns must match. (not
* implemented, can be done by modifying the query below
* to only include non-null columns, or by writing a
* special version here)
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo->confmatchtype);
break;
}
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below for all three kinds
* of MATCH.
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the real check
*/
ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_CHECK_LOOKUPPK_FROM_PK);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <pktable> WHERE pkatt1 = $1 [AND ...] FOR SHARE
* The type id's for the $ parameters are those of the
* PK attributes themselves.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(pkrelname, pk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x", pkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo->nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo->pk_attnums[i]);
quoteOneName(attname,
RIAttName(pk_rel, riinfo->pk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
attname, pk_type,
riinfo->pp_eq_oprs[i],
paramname, pk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it.
*/
result = ri_PerformCheck(riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* treat like update */
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
return result;
}
/* ----------
* RI_FKey_noaction_del -
*
* Give an error and roll back the current transaction if the
* delete has resulted in a violation of the given referential
* integrity constraint.
* ----------
*/
Datum
RI_FKey_noaction_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR SHARE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowShareLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
if (ri_Check_Pk_Match(pk_rel, fk_rel, old_row, &riinfo))
{
/*
* There's either another row, or no row could match this one. In
* either case, we don't need to do the check.
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 9) a) iv):
* MATCH SIMPLE/FULL
* ... ON DELETE NO ACTION
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the restrict delete lookup
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_NOACTION_DEL_CHECKREF);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x",
fkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL restrict delete.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_noaction_upd -
*
* Give an error and roll back the current transaction if the
* update has resulted in a violation of the given referential
* integrity constraint.
* ----------
*/
Datum
RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the new and
* old tuple.
*
* fk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR SHARE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowShareLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 10) a) iv):
* MATCH SIMPLE/FULL
* ... ON UPDATE NO ACTION
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
/*
* No need to check anything if old and new keys are equal
*/
if (ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true))
{
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
if (ri_Check_Pk_Match(pk_rel, fk_rel, old_row, &riinfo))
{
/*
* There's either another row, or no row could match this one.
* In either case, we don't need to do the check.
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the noaction update lookup
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_NOACTION_UPD_CHECKREF);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x",
fkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL noaction update.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_cascade_del -
*
* Cascaded delete foreign key references at delete event on PK table.
* ----------
*/
Datum
RI_FKey_cascade_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_cascade_del", RI_TRIGTYPE_DELETE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual DELETE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 9) a) i):
* MATCH SIMPLE/FULL
* ... ON DELETE CASCADE
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the cascaded delete
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_CASCADE_DEL_DODELETE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* DELETE FROM ONLY <fktable> WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "DELETE FROM ONLY %s", fkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Build up the arguments from the key values
* in the deleted PK tuple and delete the referencing rows
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_DELETE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL cascaded delete.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_cascade_upd -
*
* Cascaded update foreign key references at update event on PK table.
* ----------
*/
Datum
RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
int j;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_cascade_upd", RI_TRIGTYPE_UPDATE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the new and
* old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 10) a) i):
* MATCH SIMPLE/FULL
* ... ON UPDATE CASCADE
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
/*
* No need to do anything if old and new keys are equal
*/
if (ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true))
{
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the cascaded update
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_CASCADE_UPD_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS * 2];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = $1 [, ...]
* WHERE $n = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Note that we are assuming
* there is an assignment cast from the PK to the FK type;
* else the parser will fail.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE ONLY %s SET", fkrelname);
querysep = "";
qualsep = "WHERE";
for (i = 0, j = riinfo.nkeys; i < riinfo.nkeys; i++, j++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = $%d",
querysep, attname, i + 1);
sprintf(paramname, "$%d", j + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
queryoids[j] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys * 2, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, new_row,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL cascade update.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_restrict_del -
*
* Restrict delete from PK table to rows unreferenced by foreign key.
*
* The SQL standard intends that this referential action occur BEFORE
* the delete is performed, rather than after. This appears to be
* the only difference between "NO ACTION" and "RESTRICT". In Postgres
* we still implement this as an AFTER trigger, but it's non-deferrable.
* ----------
*/
Datum
RI_FKey_restrict_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_restrict_del", RI_TRIGTYPE_DELETE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR SHARE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowShareLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 9) a) iv):
* MATCH SIMPLE/FULL
* ... ON DELETE RESTRICT
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the restrict delete lookup
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_RESTRICT_DEL_CHECKREF);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x",
fkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL restrict delete.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_restrict_upd -
*
* Restrict update of PK to rows unreferenced by foreign key.
*
* The SQL standard intends that this referential action occur BEFORE
* the update is performed, rather than after. This appears to be
* the only difference between "NO ACTION" and "RESTRICT". In Postgres
* we still implement this as an AFTER trigger, but it's non-deferrable.
* ----------
*/
Datum
RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_restrict_upd", RI_TRIGTYPE_UPDATE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the new and
* old tuple.
*
* fk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR SHARE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowShareLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 10) a) iv):
* MATCH SIMPLE/FULL
* ... ON UPDATE RESTRICT
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
/*
* No need to check anything if old and new keys are equal
*/
if (ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true))
{
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the restrict update lookup
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_RESTRICT_UPD_CHECKREF);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "SELECT 1 FROM ONLY %s x",
fkrelname);
querysep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&querybuf, querysep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = "AND";
queryoids[i] = pk_type;
}
appendStringInfo(&querybuf, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL restrict update.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_setnull_del -
*
* Set foreign key references to NULL values at delete event on PK table.
* ----------
*/
Datum
RI_FKey_setnull_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setnull_del", RI_TRIGTYPE_DELETE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 9) a) ii):
* MATCH SIMPLE/FULL
* ... ON DELETE SET NULL
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set null delete operation
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETNULL_DEL_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = NULL [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE ONLY %s SET", fkrelname);
querysep = "";
qualsep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = NULL",
querysep, attname);
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL set null delete.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_setnull_upd -
*
* Set foreign key references to NULL at update event on PK table.
* ----------
*/
Datum
RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
int i;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 10) a) ii):
* MATCH SIMPLE/FULL
* ... ON UPDATE SET NULL
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
/*
* No need to do anything if old and new keys are equal
*/
if (ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true))
{
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set null update operation
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETNULL_UPD_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = NULL [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE ONLY %s SET", fkrelname);
querysep = "";
qualsep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = NULL",
querysep, attname);
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL set null update.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_setdefault_del -
*
* Set foreign key references to defaults at delete event on PK table.
* ----------
*/
Datum
RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_del", RI_TRIGTYPE_DELETE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 9) a) iii):
* MATCH SIMPLE/FULL
* ... ON DELETE SET DEFAULT
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set default delete
* operation
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETDEFAULT_DEL_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
int i;
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = DEFAULT [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE ONLY %s SET", fkrelname);
querysep = "";
qualsep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = DEFAULT",
querysep, attname);
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
/*
* In the case we delete the row who's key is equal to the default
* values AND a referencing row in the foreign key table exists,
* we would just have updated it to the same values. We need to do
* another lookup now and in case a reference exists, abort the
* operation. That is already implemented in the NO ACTION
* trigger.
*/
RI_FKey_noaction_del(fcinfo);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL set default delete.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_setdefault_upd -
*
* Set foreign key references to defaults at update event on PK table.
* ----------
*/
Datum
RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
RI_ConstraintInfo riinfo;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
SPIPlanPtr qplan;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo,
trigdata->tg_trigger, trigdata->tg_relation, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return PointerGetDatum(NULL);
/*
* Get the relation descriptors of the FK and PK tables and the old tuple.
*
* fk_rel is opened in RowExclusiveLock mode since that's what our
* eventual UPDATE will get on it.
*/
fk_rel = heap_open(riinfo.fk_relid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (riinfo.confmatchtype)
{
/* ----------
* SQL:2008 15.17 <Execution of referential actions>
* General rules 10) a) iii):
* MATCH SIMPLE/FULL
* ... ON UPDATE SET DEFAULT
* ----------
*/
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
switch (ri_NullCheck(old_row, &riinfo, true))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check needed - there cannot be any reference to old
* key if it contains a NULL
*/
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
case RI_KEYS_NONE_NULL:
/*
* Have a full qualified key - continue below
*/
break;
}
/*
* No need to do anything if old and new keys are equal
*/
if (ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true))
{
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Fetch or prepare a saved plan for the set default update
* operation
*/
ri_BuildQueryKey(&qkey, &riinfo, RI_PLAN_SETDEFAULT_UPD_DOUPDATE);
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
StringInfoData querybuf;
StringInfoData qualbuf;
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char paramname[16];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
int i;
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = DEFAULT [, ...]
* WHERE $1 = fkatt1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes.
* ----------
*/
initStringInfo(&querybuf);
initStringInfo(&qualbuf);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf, "UPDATE ONLY %s SET", fkrelname);
querysep = "";
qualsep = "WHERE";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(attname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%s %s = DEFAULT",
querysep, attname);
sprintf(paramname, "$%d", i + 1);
ri_GenerateQual(&qualbuf, qualsep,
paramname, pk_type,
riinfo.pf_eq_oprs[i],
attname, fk_type);
querysep = ",";
qualsep = "AND";
queryoids[i] = pk_type;
}
appendStringInfoString(&querybuf, qualbuf.data);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querybuf.data, riinfo.nkeys, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&riinfo, &qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(fk_rel, RowExclusiveLock);
/*
* In the case we updated the row who's key was equal to the
* default values AND a referencing row in the foreign key table
* exists, we would just have updated it to the same values. We
* need to do another lookup now and in case a reference exists,
* abort the operation. That is already implemented in the NO
* ACTION trigger.
*/
RI_FKey_noaction_upd(fcinfo);
return PointerGetDatum(NULL);
/*
* Handle MATCH PARTIAL set default update.
*/
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_keyequal_upd_pk -
*
* Check if we have a key change on an update to a PK relation. This is
* used by the AFTER trigger queue manager to see if it can skip queuing
* an instance of an RI trigger.
* ----------
*/
bool
RI_FKey_keyequal_upd_pk(Trigger *trigger, Relation pk_rel,
HeapTuple old_row, HeapTuple new_row)
{
RI_ConstraintInfo riinfo;
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo, trigger, pk_rel, true);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return true;
switch (riinfo.confmatchtype)
{
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
/* Return true if keys are equal */
return ri_KeysEqual(pk_rel, old_row, new_row, &riinfo, true);
/* Handle MATCH PARTIAL set null delete. */
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return false;
}
/* ----------
* RI_FKey_keyequal_upd_fk -
*
* Check if we have a key change on an update to an FK relation. This is
* used by the AFTER trigger queue manager to see if it can skip queuing
* an instance of an RI trigger.
* ----------
*/
bool
RI_FKey_keyequal_upd_fk(Trigger *trigger, Relation fk_rel,
HeapTuple old_row, HeapTuple new_row)
{
RI_ConstraintInfo riinfo;
/*
* Get arguments.
*/
ri_FetchConstraintInfo(&riinfo, trigger, fk_rel, false);
/*
* Nothing to do if no column names to compare given
*/
if (riinfo.nkeys == 0)
return true;
switch (riinfo.confmatchtype)
{
case FKCONSTR_MATCH_SIMPLE:
case FKCONSTR_MATCH_FULL:
/* Return true if keys are equal */
return ri_KeysEqual(fk_rel, old_row, new_row, &riinfo, false);
/* Handle MATCH PARTIAL set null delete. */
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
/* Never reached */
return false;
}
/* ----------
* RI_Initial_Check -
*
* Check an entire table for non-matching values using a single query.
* This is not a trigger procedure, but is called during ALTER TABLE
* ADD FOREIGN KEY to validate the initial table contents.
*
* We expect that the caller has made provision to prevent any problems
* caused by concurrent actions. This could be either by locking rel and
* pkrel at ShareRowExclusiveLock or higher, or by otherwise ensuring
* that triggers implementing the checks are already active.
* Hence, we do not need to lock individual rows for the check.
*
* If the check fails because the current user doesn't have permissions
* to read both tables, return false to let our caller know that they will
* need to do something else to check the constraint.
* ----------
*/
bool
RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
{
RI_ConstraintInfo riinfo;
StringInfoData querybuf;
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char pkattname[MAX_QUOTED_NAME_LEN + 3];
char fkattname[MAX_QUOTED_NAME_LEN + 3];
RangeTblEntry *pkrte;
RangeTblEntry *fkrte;
const char *sep;
int i;
int save_nestlevel;
char workmembuf[32];
int spi_result;
SPIPlanPtr qplan;
/* Fetch constraint info. */
ri_FetchConstraintInfo(&riinfo, trigger, fk_rel, false);
/*
* Check to make sure current user has enough permissions to do the test
* query. (If not, caller can fall back to the trigger method, which
* works because it changes user IDs on the fly.)
*
* XXX are there any other show-stopper conditions to check?
*/
pkrte = makeNode(RangeTblEntry);
pkrte->rtekind = RTE_RELATION;
pkrte->relid = RelationGetRelid(pk_rel);
pkrte->relkind = pk_rel->rd_rel->relkind;
pkrte->requiredPerms = ACL_SELECT;
fkrte = makeNode(RangeTblEntry);
fkrte->rtekind = RTE_RELATION;
fkrte->relid = RelationGetRelid(fk_rel);
fkrte->relkind = fk_rel->rd_rel->relkind;
fkrte->requiredPerms = ACL_SELECT;
for (i = 0; i < riinfo.nkeys; i++)
{
int attno;
attno = riinfo.pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
pkrte->selectedCols = bms_add_member(pkrte->selectedCols, attno);
attno = riinfo.fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
fkrte->selectedCols = bms_add_member(fkrte->selectedCols, attno);
}
if (!ExecCheckRTPerms(list_make2(fkrte, pkrte), false))
return false;
/*----------
* The query string built is:
* SELECT fk.keycols FROM ONLY relname fk
* LEFT OUTER JOIN ONLY pkrelname pk
* ON (pk.pkkeycol1=fk.keycol1 [AND ...])
* WHERE pk.pkkeycol1 IS NULL AND
* For MATCH SIMPLE:
* (fk.keycol1 IS NOT NULL [AND ...])
* For MATCH FULL:
* (fk.keycol1 IS NOT NULL [OR ...])
*
* We attach COLLATE clauses to the operators when comparing columns
* that have different collations.
*----------
*/
initStringInfo(&querybuf);
appendStringInfo(&querybuf, "SELECT ");
sep = "";
for (i = 0; i < riinfo.nkeys; i++)
{
quoteOneName(fkattname,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf, "%sfk.%s", sep, fkattname);
sep = ", ";
}
quoteRelationName(pkrelname, pk_rel);
quoteRelationName(fkrelname, fk_rel);
appendStringInfo(&querybuf,
" FROM ONLY %s fk LEFT OUTER JOIN ONLY %s pk ON",
fkrelname, pkrelname);
strcpy(pkattname, "pk.");
strcpy(fkattname, "fk.");
sep = "(";
for (i = 0; i < riinfo.nkeys; i++)
{
Oid pk_type = RIAttType(pk_rel, riinfo.pk_attnums[i]);
Oid fk_type = RIAttType(fk_rel, riinfo.fk_attnums[i]);
Oid pk_coll = RIAttCollation(pk_rel, riinfo.pk_attnums[i]);
Oid fk_coll = RIAttCollation(fk_rel, riinfo.fk_attnums[i]);
quoteOneName(pkattname + 3,
RIAttName(pk_rel, riinfo.pk_attnums[i]));
quoteOneName(fkattname + 3,
RIAttName(fk_rel, riinfo.fk_attnums[i]));
ri_GenerateQual(&querybuf, sep,
pkattname, pk_type,
riinfo.pf_eq_oprs[i],
fkattname, fk_type);
if (pk_coll != fk_coll)
ri_GenerateQualCollation(&querybuf, pk_coll);
sep = "AND";
}
/*
* It's sufficient to test any one pk attribute for null to detect a join
* failure.
*/
quoteOneName(pkattname, RIAttName(pk_rel, riinfo.pk_attnums[0]));
appendStringInfo(&querybuf, ") WHERE pk.%s IS NULL AND (", pkattname);
sep = "";
for (i = 0; i < riinfo.nkeys; i++)
{
quoteOneName(fkattname, RIAttName(fk_rel, riinfo.fk_attnums[i]));
appendStringInfo(&querybuf,
"%sfk.%s IS NOT NULL",
sep, fkattname);
switch (riinfo.confmatchtype)
{
case FKCONSTR_MATCH_SIMPLE:
sep = " AND ";
break;
case FKCONSTR_MATCH_FULL:
sep = " OR ";
break;
case FKCONSTR_MATCH_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
riinfo.confmatchtype);
break;
}
}
appendStringInfo(&querybuf, ")");
/*
* Temporarily increase work_mem so that the check query can be executed
* more efficiently. It seems okay to do this because the query is simple
* enough to not use a multiple of work_mem, and one typically would not
* have many large foreign-key validations happening concurrently. So
* this seems to meet the criteria for being considered a "maintenance"
* operation, and accordingly we use maintenance_work_mem.
*
* We use the equivalent of a function SET option to allow the setting to
* persist for exactly the duration of the check query. guc.c also takes
* care of undoing the setting on error.
*/
save_nestlevel = NewGUCNestLevel();
snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
(void) set_config_option("work_mem", workmembuf,
PGC_USERSET, PGC_S_SESSION,
GUC_ACTION_SAVE, true, 0);
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Generate the plan. We don't need to cache it, and there are no
* arguments to the plan.
*/
qplan = SPI_prepare(querybuf.data, 0, NULL);
if (qplan == NULL)
elog(ERROR, "SPI_prepare returned %d for %s",
SPI_result, querybuf.data);
/*
* Run the plan. For safety we force a current snapshot to be used. (In
* transaction-snapshot mode, this arguably violates transaction isolation
* rules, but we really haven't got much choice.) We don't need to
* register the snapshot, because SPI_execute_snapshot will see to it. We
* need at most one tuple returned, so pass limit = 1.
*/
spi_result = SPI_execute_snapshot(qplan,
NULL, NULL,
GetLatestSnapshot(),
InvalidSnapshot,
true, false, 1);
/* Check result */
if (spi_result != SPI_OK_SELECT)
elog(ERROR, "SPI_execute_snapshot returned %d", spi_result);
/* Did we find a tuple violating the constraint? */
if (SPI_processed > 0)
{
HeapTuple tuple = SPI_tuptable->vals[0];
TupleDesc tupdesc = SPI_tuptable->tupdesc;
/*
* The columns to look at in the result tuple are 1..N, not whatever
* they are in the fk_rel. Hack up riinfo so that the subroutines
* called here will behave properly.
*
* In addition to this, we have to pass the correct tupdesc to
* ri_ReportViolation, overriding its normal habit of using the pk_rel
* or fk_rel's tupdesc.
*/
for (i = 0; i < riinfo.nkeys; i++)
riinfo.fk_attnums[i] = i + 1;
/*
* If it's MATCH FULL, and there are any nulls in the FK keys,
* complain about that rather than the lack of a match. MATCH FULL
* disallows partially-null FK rows.
*/
if (riinfo.confmatchtype == FKCONSTR_MATCH_FULL &&
ri_NullCheck(tuple, &riinfo, false) != RI_KEYS_NONE_NULL)
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(fk_rel),
NameStr(riinfo.conname)),
errdetail("MATCH FULL does not allow mixing of null and nonnull key values.")));
/*
* We tell ri_ReportViolation we were doing the RI_PLAN_CHECK_LOOKUPPK
* query, which isn't true, but will cause it to use riinfo.fk_attnums
* as we need.
*/
ri_ReportViolation(&riinfo,
pk_rel, fk_rel,
tuple, tupdesc,
RI_PLAN_CHECK_LOOKUPPK, false);
}
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
/*
* Restore work_mem.
*/
AtEOXact_GUC(true, save_nestlevel);
return true;
}
/* ----------
* Local functions below
* ----------
*/
/*
* quoteOneName --- safely quote a single SQL name
*
* buffer must be MAX_QUOTED_NAME_LEN long (includes room for \0)
*/
static void
quoteOneName(char *buffer, const char *name)
{
/* Rather than trying to be smart, just always quote it. */
*buffer++ = '"';
while (*name)
{
if (*name == '"')
*buffer++ = '"';
*buffer++ = *name++;
}
*buffer++ = '"';
*buffer = '\0';
}
/*
* quoteRelationName --- safely quote a fully qualified relation name
*
* buffer must be MAX_QUOTED_REL_NAME_LEN long (includes room for \0)
*/
static void
quoteRelationName(char *buffer, Relation rel)
{
quoteOneName(buffer, get_namespace_name(RelationGetNamespace(rel)));
buffer += strlen(buffer);
*buffer++ = '.';
quoteOneName(buffer, RelationGetRelationName(rel));
}
/*
* ri_GenerateQual --- generate a WHERE clause equating two variables
*
* The idea is to append " sep leftop op rightop" to buf. The complexity
* comes from needing to be sure that the parser will select the desired
* operator. We always name the operator using OPERATOR(schema.op) syntax
* (readability isn't a big priority here), so as to avoid search-path
* uncertainties. We have to emit casts too, if either input isn't already
* the input type of the operator; else we are at the mercy of the parser's
* heuristics for ambiguous-operator resolution.
*/
static void
ri_GenerateQual(StringInfo buf,
const char *sep,
const char *leftop, Oid leftoptype,
Oid opoid,
const char *rightop, Oid rightoptype)
{
HeapTuple opertup;
Form_pg_operator operform;
char *oprname;
char *nspname;
opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(opoid));
if (!HeapTupleIsValid(opertup))
elog(ERROR, "cache lookup failed for operator %u", opoid);
operform = (Form_pg_operator) GETSTRUCT(opertup);
Assert(operform->oprkind == 'b');
oprname = NameStr(operform->oprname);
nspname = get_namespace_name(operform->oprnamespace);
appendStringInfo(buf, " %s %s", sep, leftop);
if (leftoptype != operform->oprleft)
ri_add_cast_to(buf, operform->oprleft);
appendStringInfo(buf, " OPERATOR(%s.", quote_identifier(nspname));
appendStringInfoString(buf, oprname);
appendStringInfo(buf, ") %s", rightop);
if (rightoptype != operform->oprright)
ri_add_cast_to(buf, operform->oprright);
ReleaseSysCache(opertup);
}
/*
* Add a cast specification to buf. We spell out the type name the hard way,
* intentionally not using format_type_be(). This is to avoid corner cases
* for CHARACTER, BIT, and perhaps other types, where specifying the type
* using SQL-standard syntax results in undesirable data truncation. By
* doing it this way we can be certain that the cast will have default (-1)
* target typmod.
*/
static void
ri_add_cast_to(StringInfo buf, Oid typid)
{
HeapTuple typetup;
Form_pg_type typform;
char *typname;
char *nspname;
typetup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
if (!HeapTupleIsValid(typetup))
elog(ERROR, "cache lookup failed for type %u", typid);
typform = (Form_pg_type) GETSTRUCT(typetup);
typname = NameStr(typform->typname);
nspname = get_namespace_name(typform->typnamespace);
appendStringInfo(buf, "::%s.%s",
quote_identifier(nspname), quote_identifier(typname));
ReleaseSysCache(typetup);
}
/*
* ri_GenerateQualCollation --- add a COLLATE spec to a WHERE clause
*
* At present, we intentionally do not use this function for RI queries that
* compare a variable to a $n parameter. Since parameter symbols always have
* default collation, the effect will be to use the variable's collation.
* Now that is only strictly correct when testing the referenced column, since
* the SQL standard specifies that RI comparisons should use the referenced
* column's collation. However, so long as all collations have the same
* notion of equality (which they do, because texteq reduces to bitwise
* equality), there's no visible semantic impact from using the referencing
* column's collation when testing it, and this is a good thing to do because
* it lets us use a normal index on the referencing column. However, we do
* have to use this function when directly comparing the referencing and
* referenced columns, if they are of different collations; else the parser
* will fail to resolve the collation to use.
*/
static void
ri_GenerateQualCollation(StringInfo buf, Oid collation)
{
HeapTuple tp;
Form_pg_collation colltup;
char *collname;
char onename[MAX_QUOTED_NAME_LEN];
/* Nothing to do if it's a noncollatable data type */
if (!OidIsValid(collation))
return;
tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collation));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for collation %u", collation);
colltup = (Form_pg_collation) GETSTRUCT(tp);
collname = NameStr(colltup->collname);
/*
* We qualify the name always, for simplicity and to ensure the query is
* not search-path-dependent.
*/
quoteOneName(onename, get_namespace_name(colltup->collnamespace));
appendStringInfo(buf, " COLLATE %s", onename);
quoteOneName(onename, collname);
appendStringInfo(buf, ".%s", onename);
ReleaseSysCache(tp);
}
/* ----------
* ri_BuildQueryKey -
*
* Construct a hashtable key for a prepared SPI plan of an FK constraint.
*
* key: output argument, *key is filled in based on the other arguments
* riinfo: info from pg_constraint entry
* constr_queryno: an internal number identifying the query type
* (see RI_PLAN_XXX constants at head of file)
* ----------
*/
static void
ri_BuildQueryKey(RI_QueryKey *key, const RI_ConstraintInfo *riinfo,
int32 constr_queryno)
{
/*
* We assume struct RI_QueryKey contains no padding bytes, else we'd
* need to use memset to clear them.
*/
key->constr_id = riinfo->constraint_id;
key->constr_queryno = constr_queryno;
}
/*
* Check that RI trigger function was called in expected context
*/
static void
ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname, int tgkind)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
if (!CALLED_AS_TRIGGER(fcinfo))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" was not called by trigger manager", funcname)));
/*
* Check proper event
*/
if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) ||
!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" must be fired AFTER ROW", funcname)));
switch (tgkind)
{
case RI_TRIGTYPE_INSERT:
if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" must be fired for INSERT", funcname)));
break;
case RI_TRIGTYPE_UPDATE:
if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" must be fired for UPDATE", funcname)));
break;
case RI_TRIGTYPE_INUP:
if (!TRIGGER_FIRED_BY_INSERT(trigdata->tg_event) &&
!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" must be fired for INSERT or UPDATE",
funcname)));
break;
case RI_TRIGTYPE_DELETE:
if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" must be fired for DELETE", funcname)));
break;
}
}
/*
* Fetch the pg_constraint entry for the FK constraint, and fill *riinfo
*/
static void
ri_FetchConstraintInfo(RI_ConstraintInfo *riinfo,
Trigger *trigger, Relation trig_rel, bool rel_is_pk)
{
Oid constraintOid = trigger->tgconstraint;
HeapTuple tup;
Form_pg_constraint conForm;
Datum adatum;
bool isNull;
ArrayType *arr;
int numkeys;
/*
* Check that the FK constraint's OID is available; it might not be if
* we've been invoked via an ordinary trigger or an old-style "constraint
* trigger".
*/
if (!OidIsValid(constraintOid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("no pg_constraint entry for trigger \"%s\" on table \"%s\"",
trigger->tgname, RelationGetRelationName(trig_rel)),
errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
/* OK, fetch the tuple */
tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", constraintOid);
conForm = (Form_pg_constraint) GETSTRUCT(tup);
/* Do some easy cross-checks against the trigger call data */
if (rel_is_pk)
{
if (conForm->contype != CONSTRAINT_FOREIGN ||
conForm->conrelid != trigger->tgconstrrelid ||
conForm->confrelid != RelationGetRelid(trig_rel))
elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
trigger->tgname, RelationGetRelationName(trig_rel));
}
else
{
if (conForm->contype != CONSTRAINT_FOREIGN ||
conForm->conrelid != RelationGetRelid(trig_rel) ||
conForm->confrelid != trigger->tgconstrrelid)
elog(ERROR, "wrong pg_constraint entry for trigger \"%s\" on table \"%s\"",
trigger->tgname, RelationGetRelationName(trig_rel));
}
/* And extract data */
riinfo->constraint_id = constraintOid;
memcpy(&riinfo->conname, &conForm->conname, sizeof(NameData));
riinfo->pk_relid = conForm->confrelid;
riinfo->fk_relid = conForm->conrelid;
riinfo->confupdtype = conForm->confupdtype;
riinfo->confdeltype = conForm->confdeltype;
riinfo->confmatchtype = conForm->confmatchtype;
/*
* We expect the arrays to be 1-D arrays of the right types; verify that.
* We don't need to use deconstruct_array() since the array data is just
* going to look like a C array of values.
*/
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conkey, &isNull);
if (isNull)
elog(ERROR, "null conkey for constraint %u", constraintOid);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
if (ARR_NDIM(arr) != 1 ||
numkeys < 0 ||
numkeys > RI_MAX_NUMKEYS ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != INT2OID)
elog(ERROR, "conkey is not a 1-D smallint array");
riinfo->nkeys = numkeys;
memcpy(riinfo->fk_attnums, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
if ((Pointer) arr != DatumGetPointer(adatum))
pfree(arr); /* free de-toasted copy, if any */
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_confkey, &isNull);
if (isNull)
elog(ERROR, "null confkey for constraint %u", constraintOid);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
if (ARR_NDIM(arr) != 1 ||
numkeys != riinfo->nkeys ||
numkeys > RI_MAX_NUMKEYS ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != INT2OID)
elog(ERROR, "confkey is not a 1-D smallint array");
memcpy(riinfo->pk_attnums, ARR_DATA_PTR(arr), numkeys * sizeof(int16));
if ((Pointer) arr != DatumGetPointer(adatum))
pfree(arr); /* free de-toasted copy, if any */
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conpfeqop, &isNull);
if (isNull)
elog(ERROR, "null conpfeqop for constraint %u", constraintOid);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
/* see TryReuseForeignKey if you change the test below */
if (ARR_NDIM(arr) != 1 ||
numkeys != riinfo->nkeys ||
numkeys > RI_MAX_NUMKEYS ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != OIDOID)
elog(ERROR, "conpfeqop is not a 1-D Oid array");
memcpy(riinfo->pf_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
if ((Pointer) arr != DatumGetPointer(adatum))
pfree(arr); /* free de-toasted copy, if any */
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conppeqop, &isNull);
if (isNull)
elog(ERROR, "null conppeqop for constraint %u", constraintOid);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
if (ARR_NDIM(arr) != 1 ||
numkeys != riinfo->nkeys ||
numkeys > RI_MAX_NUMKEYS ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != OIDOID)
elog(ERROR, "conppeqop is not a 1-D Oid array");
memcpy(riinfo->pp_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
if ((Pointer) arr != DatumGetPointer(adatum))
pfree(arr); /* free de-toasted copy, if any */
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conffeqop, &isNull);
if (isNull)
elog(ERROR, "null conffeqop for constraint %u", constraintOid);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
if (ARR_NDIM(arr) != 1 ||
numkeys != riinfo->nkeys ||
numkeys > RI_MAX_NUMKEYS ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != OIDOID)
elog(ERROR, "conffeqop is not a 1-D Oid array");
memcpy(riinfo->ff_eq_oprs, ARR_DATA_PTR(arr), numkeys * sizeof(Oid));
if ((Pointer) arr != DatumGetPointer(adatum))
pfree(arr); /* free de-toasted copy, if any */
ReleaseSysCache(tup);
}
/*
* Prepare execution plan for a query to enforce an RI restriction
*
* If cache_plan is true, the plan is saved into our plan hashtable
* so that we don't need to plan it again.
*/
static SPIPlanPtr
ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
bool cache_plan)
{
SPIPlanPtr qplan;
Relation query_rel;
Oid save_userid;
int save_sec_context;
/*
* Use the query type code to determine whether the query is run against
* the PK or FK table; we'll do the check as that table's owner
*/
if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
query_rel = pk_rel;
else
query_rel = fk_rel;
/* Switch to proper UID to perform check as */
GetUserIdAndSecContext(&save_userid, &save_sec_context);
SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
/* Create the plan */
qplan = SPI_prepare(querystr, nargs, argtypes);
if (qplan == NULL)
elog(ERROR, "SPI_prepare returned %d for %s", SPI_result, querystr);
/* Restore UID and security context */
SetUserIdAndSecContext(save_userid, save_sec_context);
/* Save the plan if requested */
if (cache_plan)
{
SPI_keepplan(qplan);
ri_HashPreparedPlan(qkey, qplan);
}
return qplan;
}
/*
* Perform a query to enforce an RI restriction
*/
static bool
ri_PerformCheck(const RI_ConstraintInfo *riinfo,
RI_QueryKey *qkey, SPIPlanPtr qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows, int expect_OK)
{
Relation query_rel,
source_rel;
bool source_is_pk;
Snapshot test_snapshot;
Snapshot crosscheck_snapshot;
int limit;
int spi_result;
Oid save_userid;
int save_sec_context;
Datum vals[RI_MAX_NUMKEYS * 2];
char nulls[RI_MAX_NUMKEYS * 2];
/*
* Use the query type code to determine whether the query is run against
* the PK or FK table; we'll do the check as that table's owner
*/
if (qkey->constr_queryno <= RI_PLAN_LAST_ON_PK)
query_rel = pk_rel;
else
query_rel = fk_rel;
/*
* The values for the query are taken from the table on which the trigger
* is called - it is normally the other one with respect to query_rel.
* An exception is ri_Check_Pk_Match(), which uses the PK table for both
* (and sets queryno to RI_PLAN_CHECK_LOOKUPPK_FROM_PK). We might
* eventually need some less klugy way to determine this.
*/
if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK)
{
source_rel = fk_rel;
source_is_pk = false;
}
else
{
source_rel = pk_rel;
source_is_pk = true;
}
/* Extract the parameters to be passed into the query */
if (new_tuple)
{
ri_ExtractValues(source_rel, new_tuple, riinfo, source_is_pk,
vals, nulls);
if (old_tuple)
ri_ExtractValues(source_rel, old_tuple, riinfo, source_is_pk,
vals + riinfo->nkeys, nulls + riinfo->nkeys);
}
else
{
ri_ExtractValues(source_rel, old_tuple, riinfo, source_is_pk,
vals, nulls);
}
/*
* In READ COMMITTED mode, we just need to use an up-to-date regular
* snapshot, and we will see all rows that could be interesting. But in
* transaction-snapshot mode, we can't change the transaction snapshot. If
* the caller passes detectNewRows == false then it's okay to do the query
* with the transaction snapshot; otherwise we use a current snapshot, and
* tell the executor to error out if it finds any rows under the current
* snapshot that wouldn't be visible per the transaction snapshot. Note
* that SPI_execute_snapshot will register the snapshots, so we don't need
* to bother here.
*/
if (IsolationUsesXactSnapshot() && detectNewRows)
{
CommandCounterIncrement(); /* be sure all my own work is visible */
test_snapshot = GetLatestSnapshot();
crosscheck_snapshot = GetTransactionSnapshot();
}
else
{
/* the default SPI behavior is okay */
test_snapshot = InvalidSnapshot;
crosscheck_snapshot = InvalidSnapshot;
}
/*
* If this is a select query (e.g., for a 'no action' or 'restrict'
* trigger), we only need to see if there is a single row in the table,
* matching the key. Otherwise, limit = 0 - because we want the query to
* affect ALL the matching rows.
*/
limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
/* Switch to proper UID to perform check as */
GetUserIdAndSecContext(&save_userid, &save_sec_context);
SetUserIdAndSecContext(RelationGetForm(query_rel)->relowner,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
/* Finally we can run the query. */
spi_result = SPI_execute_snapshot(qplan,
vals, nulls,
test_snapshot, crosscheck_snapshot,
false, false, limit);
/* Restore UID and security context */
SetUserIdAndSecContext(save_userid, save_sec_context);
/* Check result */
if (spi_result < 0)
elog(ERROR, "SPI_execute_snapshot returned %d", spi_result);
if (expect_OK >= 0 && spi_result != expect_OK)
ri_ReportViolation(riinfo,
pk_rel, fk_rel,
new_tuple ? new_tuple : old_tuple,
NULL,
qkey->constr_queryno, true);
/* XXX wouldn't it be clearer to do this part at the caller? */
if (qkey->constr_queryno != RI_PLAN_CHECK_LOOKUPPK_FROM_PK &&
expect_OK == SPI_OK_SELECT &&
(SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
ri_ReportViolation(riinfo,
pk_rel, fk_rel,
new_tuple ? new_tuple : old_tuple,
NULL,
qkey->constr_queryno, false);
return SPI_processed != 0;
}
/*
* Extract fields from a tuple into Datum/nulls arrays
*/
static void
ri_ExtractValues(Relation rel, HeapTuple tup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk,
Datum *vals, char *nulls)
{
TupleDesc tupdesc = rel->rd_att;
const int16 *attnums;
int i;
bool isnull;
if (rel_is_pk)
attnums = riinfo->pk_attnums;
else
attnums = riinfo->fk_attnums;
for (i = 0; i < riinfo->nkeys; i++)
{
vals[i] = heap_getattr(tup, attnums[i], tupdesc,
&isnull);
nulls[i] = isnull ? 'n' : ' ';
}
}
/*
* Produce an error report
*
* If the failed constraint was on insert/update to the FK table,
* we want the key names and values extracted from there, and the error
* message to look like 'key blah is not present in PK'.
* Otherwise, the attr names and values come from the PK table and the
* message looks like 'key blah is still referenced from FK'.
*/
static void
ri_ReportViolation(const RI_ConstraintInfo *riinfo,
Relation pk_rel, Relation fk_rel,
HeapTuple violator, TupleDesc tupdesc,
int queryno, bool spi_err)
{
StringInfoData key_names;
StringInfoData key_values;
bool onfk;
const int16 *attnums;
int idx;
if (spi_err)
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("referential integrity query on \"%s\" from constraint \"%s\" on \"%s\" gave unexpected result",
RelationGetRelationName(pk_rel),
NameStr(riinfo->conname),
RelationGetRelationName(fk_rel)),
errhint("This is most likely due to a rule having rewritten the query.")));
/*
* Determine which relation to complain about. If tupdesc wasn't passed
* by caller, assume the violator tuple came from there.
*/
onfk = (queryno == RI_PLAN_CHECK_LOOKUPPK);
if (onfk)
{
attnums = riinfo->fk_attnums;
if (tupdesc == NULL)
tupdesc = fk_rel->rd_att;
}
else
{
attnums = riinfo->pk_attnums;
if (tupdesc == NULL)
tupdesc = pk_rel->rd_att;
}
/*
* Special case - if there are no keys at all, this is a 'no column'
* constraint - no need to try to extract the values, and the message in
* this case looks different.
*/
if (riinfo->nkeys == 0)
{
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(fk_rel),
NameStr(riinfo->conname)),
errdetail("No rows were found in \"%s\".",
RelationGetRelationName(pk_rel))));
}
/* Get printable versions of the keys involved */
initStringInfo(&key_names);
initStringInfo(&key_values);
for (idx = 0; idx < riinfo->nkeys; idx++)
{
int fnum = attnums[idx];
char *name,
*val;
name = SPI_fname(tupdesc, fnum);
val = SPI_getvalue(violator, tupdesc, fnum);
if (!val)
val = "null";
if (idx > 0)
{
appendStringInfoString(&key_names, ", ");
appendStringInfoString(&key_values, ", ");
}
appendStringInfoString(&key_names, name);
appendStringInfoString(&key_values, val);
}
if (onfk)
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(fk_rel),
NameStr(riinfo->conname)),
errdetail("Key (%s)=(%s) is not present in table \"%s\".",
key_names.data, key_values.data,
RelationGetRelationName(pk_rel))));
else
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("update or delete on table \"%s\" violates foreign key constraint \"%s\" on table \"%s\"",
RelationGetRelationName(pk_rel),
NameStr(riinfo->conname),
RelationGetRelationName(fk_rel)),
errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
key_names.data, key_values.data,
RelationGetRelationName(fk_rel))));
}
/* ----------
* ri_NullCheck -
*
* Determine the NULL state of all key values in a tuple
*
* Returns one of RI_KEYS_ALL_NULL, RI_KEYS_NONE_NULL or RI_KEYS_SOME_NULL.
* ----------
*/
static int
ri_NullCheck(HeapTuple tup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk)
{
const int16 *attnums;
int i;
bool allnull = true;
bool nonenull = true;
if (rel_is_pk)
attnums = riinfo->pk_attnums;
else
attnums = riinfo->fk_attnums;
for (i = 0; i < riinfo->nkeys; i++)
{
if (heap_attisnull(tup, attnums[i]))
nonenull = false;
else
allnull = false;
}
if (allnull)
return RI_KEYS_ALL_NULL;
if (nonenull)
return RI_KEYS_NONE_NULL;
return RI_KEYS_SOME_NULL;
}
/* ----------
* ri_InitHashTables -
*
* Initialize our internal hash tables for prepared
* query plans and comparison operators.
* ----------
*/
static void
ri_InitHashTables(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(RI_QueryKey);
ctl.entrysize = sizeof(RI_QueryHashEntry);
ctl.hash = tag_hash;
ri_query_cache = hash_create("RI query cache", RI_INIT_QUERYHASHSIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(RI_CompareKey);
ctl.entrysize = sizeof(RI_CompareHashEntry);
ctl.hash = tag_hash;
ri_compare_cache = hash_create("RI compare cache", RI_INIT_QUERYHASHSIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
}
/* ----------
* ri_FetchPreparedPlan -
*
* Lookup for a query key in our private hash table of prepared
* and saved SPI execution plans. Return the plan if found or NULL.
* ----------
*/
static SPIPlanPtr
ri_FetchPreparedPlan(RI_QueryKey *key)
{
RI_QueryHashEntry *entry;
SPIPlanPtr plan;
/*
* On the first call initialize the hashtable
*/
if (!ri_query_cache)
ri_InitHashTables();
/*
* Lookup for the key
*/
entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
(void *) key,
HASH_FIND, NULL);
if (entry == NULL)
return NULL;
/*
* Check whether the plan is still valid. If it isn't, we don't want to
* simply rely on plancache.c to regenerate it; rather we should start
* from scratch and rebuild the query text too. This is to cover cases
* such as table/column renames. We depend on the plancache machinery to
* detect possible invalidations, though.
*
* CAUTION: this check is only trustworthy if the caller has already
* locked both FK and PK rels.
*/
plan = entry->plan;
if (plan && SPI_plan_is_valid(plan))
return plan;
/*
* Otherwise we might as well flush the cached plan now, to free a little
* memory space before we make a new one.
*/
entry->plan = NULL;
if (plan)
SPI_freeplan(plan);
return NULL;
}
/* ----------
* ri_HashPreparedPlan -
*
* Add another plan to our private SPI query plan hashtable.
* ----------
*/
static void
ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan)
{
RI_QueryHashEntry *entry;
bool found;
/*
* On the first call initialize the hashtable
*/
if (!ri_query_cache)
ri_InitHashTables();
/*
* Add the new plan. We might be overwriting an entry previously found
* invalid by ri_FetchPreparedPlan.
*/
entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
(void *) key,
HASH_ENTER, &found);
Assert(!found || entry->plan == NULL);
entry->plan = plan;
}
/* ----------
* ri_KeysEqual -
*
* Check if all key values in OLD and NEW are equal.
* ----------
*/
static bool
ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
const RI_ConstraintInfo *riinfo, bool rel_is_pk)
{
TupleDesc tupdesc = RelationGetDescr(rel);
const int16 *attnums;
const Oid *eq_oprs;
int i;
if (rel_is_pk)
{
attnums = riinfo->pk_attnums;
eq_oprs = riinfo->pp_eq_oprs;
}
else
{
attnums = riinfo->fk_attnums;
eq_oprs = riinfo->ff_eq_oprs;
}
for (i = 0; i < riinfo->nkeys; i++)
{
Datum oldvalue;
Datum newvalue;
bool isnull;
/*
* Get one attribute's oldvalue. If it is NULL - they're not equal.
*/
oldvalue = heap_getattr(oldtup, attnums[i], tupdesc, &isnull);
if (isnull)
return false;
/*
* Get one attribute's newvalue. If it is NULL - they're not equal.
*/
newvalue = heap_getattr(newtup, attnums[i], tupdesc, &isnull);
if (isnull)
return false;
/*
* Compare them with the appropriate equality operator.
*/
if (!ri_AttributesEqual(eq_oprs[i], RIAttType(rel, attnums[i]),
oldvalue, newvalue))
return false;
}
return true;
}
/* ----------
* ri_AttributesEqual -
*
* Call the appropriate equality comparison operator for two values.
*
* NB: we have already checked that neither value is null.
* ----------
*/
static bool
ri_AttributesEqual(Oid eq_opr, Oid typeid,
Datum oldvalue, Datum newvalue)
{
RI_CompareHashEntry *entry = ri_HashCompareOp(eq_opr, typeid);
/* Do we need to cast the values? */
if (OidIsValid(entry->cast_func_finfo.fn_oid))
{
oldvalue = FunctionCall3(&entry->cast_func_finfo,
oldvalue,
Int32GetDatum(-1), /* typmod */
BoolGetDatum(false)); /* implicit coercion */
newvalue = FunctionCall3(&entry->cast_func_finfo,
newvalue,
Int32GetDatum(-1), /* typmod */
BoolGetDatum(false)); /* implicit coercion */
}
/*
* Apply the comparison operator. We assume it doesn't care about
* collations.
*/
return DatumGetBool(FunctionCall2(&entry->eq_opr_finfo,
oldvalue, newvalue));
}
/* ----------
* ri_HashCompareOp -
*
* See if we know how to compare two values, and create a new hash entry
* if not.
* ----------
*/
static RI_CompareHashEntry *
ri_HashCompareOp(Oid eq_opr, Oid typeid)
{
RI_CompareKey key;
RI_CompareHashEntry *entry;
bool found;
/*
* On the first call initialize the hashtable
*/
if (!ri_compare_cache)
ri_InitHashTables();
/*
* Find or create a hash entry. Note we're assuming RI_CompareKey
* contains no struct padding.
*/
key.eq_opr = eq_opr;
key.typeid = typeid;
entry = (RI_CompareHashEntry *) hash_search(ri_compare_cache,
(void *) &key,
HASH_ENTER, &found);
if (!found)
entry->valid = false;
/*
* If not already initialized, do so. Since we'll keep this hash entry
* for the life of the backend, put any subsidiary info for the function
* cache structs into TopMemoryContext.
*/
if (!entry->valid)
{
Oid lefttype,
righttype,
castfunc;
CoercionPathType pathtype;
/* We always need to know how to call the equality operator */
fmgr_info_cxt(get_opcode(eq_opr), &entry->eq_opr_finfo,
TopMemoryContext);
/*
* If we chose to use a cast from FK to PK type, we may have to apply
* the cast function to get to the operator's input type.
*
* XXX eventually it would be good to support array-coercion cases
* here and in ri_AttributesEqual(). At the moment there is no point
* because cases involving nonidentical array types will be rejected
* at constraint creation time.
*
* XXX perhaps also consider supporting CoerceViaIO? No need at the
* moment since that will never be generated for implicit coercions.
*/
op_input_types(eq_opr, &lefttype, &righttype);
Assert(lefttype == righttype);
if (typeid == lefttype)
castfunc = InvalidOid; /* simplest case */
else
{
pathtype = find_coercion_pathway(lefttype, typeid,
COERCION_IMPLICIT,
&castfunc);
if (pathtype != COERCION_PATH_FUNC &&
pathtype != COERCION_PATH_RELABELTYPE)
{
/*
* The declared input type of the eq_opr might be a
* polymorphic type such as ANYARRAY or ANYENUM, or other
* special cases such as RECORD; find_coercion_pathway
* currently doesn't subsume these special cases.
*/
if (!IsPolymorphicType(lefttype) &&
!IsBinaryCoercible(typeid, lefttype))
elog(ERROR, "no conversion function from %s to %s",
format_type_be(typeid),
format_type_be(lefttype));
}
}
if (OidIsValid(castfunc))
fmgr_info_cxt(castfunc, &entry->cast_func_finfo,
TopMemoryContext);
else
entry->cast_func_finfo.fn_oid = InvalidOid;
entry->valid = true;
}
return entry;
}
/*
* Given a trigger function OID, determine whether it is an RI trigger,
* and if so whether it is attached to PK or FK relation.
*/
int
RI_FKey_trigger_type(Oid tgfoid)
{
switch (tgfoid)
{
case F_RI_FKEY_CASCADE_DEL:
case F_RI_FKEY_CASCADE_UPD:
case F_RI_FKEY_RESTRICT_DEL:
case F_RI_FKEY_RESTRICT_UPD:
case F_RI_FKEY_SETNULL_DEL:
case F_RI_FKEY_SETNULL_UPD:
case F_RI_FKEY_SETDEFAULT_DEL:
case F_RI_FKEY_SETDEFAULT_UPD:
case F_RI_FKEY_NOACTION_DEL:
case F_RI_FKEY_NOACTION_UPD:
return RI_TRIGGER_PK;
case F_RI_FKEY_CHECK_INS:
case F_RI_FKEY_CHECK_UPD:
return RI_TRIGGER_FK;
}
return RI_TRIGGER_NONE;
}
View Git Blame Copy Permalink