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postgres/src/backend/utils/adt/ri_triggers.c
Tom Lane 3af35f8d40 Make standard maintenance operations (including VACUUM, ANALYZE, REINDEX, 
and CLUSTER) execute as the table owner rather than the calling user, using
the same privilege-switching mechanism already used for SECURITY DEFINER
functions.  The purpose of this change is to ensure that user-defined
functions used in index definitions cannot acquire the privileges of a
superuser account that is performing routine maintenance.  While a function
used in an index is supposed to be IMMUTABLE and thus not able to do anything
very interesting, there are several easy ways around that restriction; and
even if we could plug them all, there would remain a risk of reading sensitive
information and broadcasting it through a covert channel such as CPU usage.

To prevent bypassing this security measure, execution of SET SESSION
AUTHORIZATION and SET ROLE is now forbidden within a SECURITY DEFINER context.

Thanks to Itagaki Takahiro for reporting this vulnerability.

Security: CVE-2007-6600
2008-01-03 21:23:45 +00:00

3686 lines
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/* ----------
* 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 parse/plan node trees they point to are copied into
* TopMemoryContext using SPI_saveplan(). This is pretty ugly, since there
* is no way to free a no-longer-needed plan tree, but then again we don't
* yet have any bookkeeping that would allow us to detect that a plan isn't
* needed anymore. Improve it someday.
*
*
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.89.2.2 2008/01/03 21:23:45 tgl Exp $
*
* ----------
*/
/* ----------
* Internal TODO:
*
* Add MATCH PARTIAL logic.
* ----------
*/
#include "postgres.h"
#include "commands/trigger.h"
#include "executor/spi_priv.h"
#include "utils/acl.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/typcache.h"
#include "miscadmin.h"
/* ----------
* Local definitions
* ----------
*/
#define RI_INIT_QUERYHASHSIZE 128
#define RI_MATCH_TYPE_UNSPECIFIED 0
#define RI_MATCH_TYPE_FULL 1
#define RI_MATCH_TYPE_PARTIAL 2
#define RI_KEYS_ALL_NULL 0
#define RI_KEYS_SOME_NULL 1
#define RI_KEYS_NONE_NULL 2
/* queryno values must be distinct for the convenience of ri_PerformCheck */
#define RI_PLAN_CHECK_LOOKUPPK_NOCOLS 1
#define RI_PLAN_CHECK_LOOKUPPK 2
#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_KEYEQUAL_UPD 11
#define MAX_QUOTED_NAME_LEN (NAMEDATALEN*2+3)
#define MAX_QUOTED_REL_NAME_LEN (MAX_QUOTED_NAME_LEN*2)
#define RI_TRIGTYPE_INSERT 1
#define RI_TRIGTYPE_UPDATE 2
#define RI_TRIGTYPE_INUP 3
#define RI_TRIGTYPE_DELETE 4
/* ----------
* RI_QueryKey
*
* The key identifying a prepared SPI plan in our private hashtable
* ----------
*/
typedef struct RI_QueryKey
{
int32 constr_type;
Oid constr_id;
int32 constr_queryno;
Oid fk_relid;
Oid pk_relid;
int32 nkeypairs;
int16 keypair[RI_MAX_NUMKEYS][2];
} RI_QueryKey;
/* ----------
* RI_QueryHashEntry
* ----------
*/
typedef struct RI_QueryHashEntry
{
RI_QueryKey key;
void *plan;
} RI_QueryHashEntry;
/* ----------
* Local data
* ----------
*/
static HTAB *ri_query_cache = NULL;
/* ----------
* Local function prototypes
* ----------
*/
static void quoteOneName(char *buffer, const char *name);
static void quoteRelationName(char *buffer, Relation rel);
static int ri_DetermineMatchType(char *str);
static int ri_NullCheck(Relation rel, HeapTuple tup,
RI_QueryKey *key, int pairidx);
static void ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id,
int32 constr_queryno,
Relation fk_rel, Relation pk_rel,
int argc, char **argv);
static void ri_BuildQueryKeyPkCheck(RI_QueryKey *key, Oid constr_id,
int32 constr_queryno,
Relation pk_rel,
int argc, char **argv);
static bool ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx);
static bool ri_AllKeysUnequal(Relation rel, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx);
static bool ri_OneKeyEqual(Relation rel, int column, HeapTuple oldtup,
HeapTuple newtup, RI_QueryKey *key, int pairidx);
static bool ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue);
static bool ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
HeapTuple old_row,
Oid tgoid, int match_type,
int tgnargs, char **tgargs);
static void ri_InitHashTables(void);
static void *ri_FetchPreparedPlan(RI_QueryKey *key);
static void ri_HashPreparedPlan(RI_QueryKey *key, void *plan);
static void ri_CheckTrigger(FunctionCallInfo fcinfo, const char *funcname,
int tgkind);
static void *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(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows,
int expect_OK, const char *constrname);
static void ri_ExtractValues(RI_QueryKey *qkey, int key_idx,
Relation rel, HeapTuple tuple,
Datum *vals, char *nulls);
static void ri_ReportViolation(RI_QueryKey *qkey, const char *constrname,
Relation pk_rel, Relation fk_rel,
HeapTuple violator, TupleDesc tupdesc,
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
Buffer new_row_buf;
RI_QueryKey qkey;
void *qplan;
int i;
int match_type;
/*
* 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.
*/
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
old_row = trigdata->tg_trigtuple;
new_row = trigdata->tg_newtuple;
new_row_buf = trigdata->tg_newtuplebuf;
}
else
{
old_row = NULL;
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 with HeapTupleSatisfiesItself.
*
* NOTE: The normal coding rule is that one must acquire the buffer
* content lock to call HeapTupleSatisfiesFOO. 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 (!HeapTupleSatisfiesItself(new_row->t_data, 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(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
/* ----------
* SQL3 11.9 <referential constraint definition>
* General rules 2) a):
* 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 up to now in Postgres, it's just there for
* future enhancements.
* ----------
*/
if (tgnargs == 4)
{
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_CHECK_LOOKUPPK_NOCOLS,
fk_rel, pk_rel,
tgnargs, tgargs);
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
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(&qkey, qplan,
fk_rel, pk_rel,
NULL, NULL,
false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
if (match_type == RI_MATCH_TYPE_PARTIAL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_CHECK_LOOKUPPK, fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(fk_rel, new_row, &qkey, RI_KEYPAIR_FK_IDX))
{
case RI_KEYS_ALL_NULL:
/*
* No check - if NULLs are allowed at all is already checked by
* NOT NULL constraint.
*
* This is true for MATCH FULL, MATCH PARTIAL, and MATCH
* <unspecified>
*/
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 (match_type)
{
case RI_MATCH_TYPE_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),
tgargs[RI_CONSTRAINT_NAME_ARGNO]),
errdetail("MATCH FULL does not allow mixing of null and nonnull key values.")));
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_MATCH_TYPE_UNSPECIFIED:
/*
* MATCH <unspecified> - if ANY column is null, we have a
* match.
*/
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
case RI_MATCH_TYPE_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);
}
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
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <pktable> WHERE pkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding FK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(pkrelname, pk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", pkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_PK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(fk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_FK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* Now check that foreign key exists in PK table
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
NULL, new_row,
false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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,
Oid tgoid, int match_type,
int tgnargs, char **tgargs)
{
void *qplan;
RI_QueryKey qkey;
int i;
bool result;
ri_BuildQueryKeyPkCheck(&qkey, tgoid,
RI_PLAN_CHECK_LOOKUPPK, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
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 (match_type)
{
case RI_MATCH_TYPE_FULL:
case RI_MATCH_TYPE_UNSPECIFIED:
/*
* MATCH <unspecified>/FULL - if ANY column is null, we
* can't be matching to this row already.
*/
return true;
case RI_MATCH_TYPE_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;
}
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
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <pktable> WHERE pkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding FK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(pkrelname, pk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", pkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_PK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it.
*/
result = ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* treat like update */
SPI_OK_SELECT, NULL);
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
int i;
int match_type;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_noaction_del", RI_TRIGTYPE_DELETE);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
if (ri_Check_Pk_Match(pk_rel, fk_rel,
old_row, trigdata->tg_trigger->tgoid,
match_type, tgnargs, tgargs))
{
/*
* 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 (match_type)
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) iv):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_NOACTION_DEL_CHECKREF,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains 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 if
* foreign references exist
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", fkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
int i;
int match_type;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_noaction_upd", RI_TRIGTYPE_UPDATE);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
switch (match_type)
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) iv):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_NOACTION_UPD_CHECKREF,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains 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, &qkey,
RI_KEYPAIR_PK_IDX))
{
heap_close(fk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
if (ri_Check_Pk_Match(pk_rel, fk_rel,
old_row, trigdata->tg_trigger->tgoid,
match_type, tgnargs, tgargs))
{
/*
* 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 if
* foreign references exist
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", fkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) i):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_CASCADE_DEL_DODELETE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains 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
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* DELETE FROM ONLY <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "DELETE FROM ONLY %s", fkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, 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(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_DELETE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_cascade_upd -
*
* Cascaded update/delete foreign key references at update event on PK table.
* ----------
*/
Datum
RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 7) a) i):
* MATCH <unspecified> or MATCH FULL
* ... ON UPDATE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_CASCADE_UPD_DOUPDATE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No update - MATCH FULL means there cannot be any
* reference to old key if it contains 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, &qkey,
RI_KEYPAIR_PK_IDX))
{
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 of
* foreign references
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS * 2];
char qualstr[(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS * 2];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = $1 [, ...]
* WHERE fkatt1 = $n [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "UPDATE ONLY %s SET", fkrelname);
qualstr[0] = '\0';
querysep = "";
qualsep = "WHERE";
for (i = 0, j = qkey.nkeypairs; i < qkey.nkeypairs; i++, j++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), "%s %s = $%d",
querysep, attname, i + 1);
snprintf(qualstr + strlen(qualstr), sizeof(qualstr) - strlen(qualstr), " %s %s = $%d",
qualsep, attname, j + 1);
querysep = ",";
qualsep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
queryoids[j] = queryoids[i];
}
strcat(querystr, qualstr);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs * 2, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, new_row,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_restrict_del -
*
* Restrict delete from PK table to rows unreferenced by foreign key.
*
* SQL3 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".
*
* For now, however, we treat "RESTRICT" and "NO ACTION" as
* equivalent.
* ----------
*/
Datum
RI_FKey_restrict_del(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) iv):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_RESTRICT_DEL_CHECKREF,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains 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 if
* foreign references exist
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", fkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
return PointerGetDatum(NULL);
}
/* ----------
* RI_FKey_restrict_upd -
*
* Restrict update of PK to rows unreferenced by foreign key.
*
* SQL3 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".
*
* For now, however, we treat "RESTRICT" and "NO ACTION" as
* equivalent.
* ----------
*/
Datum
RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) iv):
* MATCH <unspecified> or MATCH FULL
* ... ON DELETE CASCADE
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_RESTRICT_UPD_CHECKREF,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No check - MATCH FULL means there cannot be any
* reference to old key if it contains 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, &qkey,
RI_KEYPAIR_PK_IDX))
{
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 if
* foreign references exist
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* SELECT 1 FROM ONLY <fktable> WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "SELECT 1 FROM ONLY %s x", fkrelname);
querysep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), " %s %s = $%d",
querysep, attname, i + 1);
querysep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, " FOR SHARE OF x");
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) ii):
* MATCH <UNSPECIFIED> or MATCH FULL
* ... ON DELETE SET NULL
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_SETNULL_DEL_DOUPDATE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No update - MATCH FULL means there cannot be any
* reference to old key if it contains 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
*/
if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS * 2];
char qualstr[(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = NULL [, ...]
* WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "UPDATE ONLY %s SET", fkrelname);
qualstr[0] = '\0';
querysep = "";
qualsep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), "%s %s = NULL",
querysep, attname);
snprintf(qualstr + strlen(qualstr), sizeof(qualstr) - strlen(qualstr), " %s %s = $%d",
qualsep, attname, i + 1);
querysep = ",";
qualsep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, qualstr);
/* Prepare and save the plan */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, true);
}
/*
* We have a plan now. Run it to check for existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
int i;
int match_type;
bool use_cached_query;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setnull_upd", RI_TRIGTYPE_UPDATE);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
switch (match_type)
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 7) a) ii) 2):
* MATCH FULL
* ... ON UPDATE SET NULL
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_SETNULL_UPD_DOUPDATE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No update - MATCH FULL means there cannot be any
* reference to old key if it contains 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, &qkey,
RI_KEYPAIR_PK_IDX))
{
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* "MATCH <unspecified>" only changes columns corresponding to the
* referenced columns that have changed in pk_rel. This means the
* "SET attrn=NULL [, attrn=NULL]" string will be change as well.
* In this case, we need to build a temporary plan rather than use
* our cached plan, unless the update happens to change all
* columns in the key. Fortunately, for the most common case of a
* single-column foreign key, this will be true.
*
* In case you're wondering, the inequality check works because we
* know that the old key value has no NULLs (see above).
*/
use_cached_query = match_type == RI_MATCH_TYPE_FULL ||
ri_AllKeysUnequal(pk_rel, old_row, new_row,
&qkey, RI_KEYPAIR_PK_IDX);
/*
* Fetch or prepare a saved plan for the set null update operation
* if possible, or build a temporary plan if not.
*/
if (!use_cached_query ||
(qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS * 2];
char qualstr[(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
const char *querysep;
const char *qualsep;
Oid queryoids[RI_MAX_NUMKEYS];
/* ----------
* The query string built is
* UPDATE ONLY <fktable> SET fkatt1 = NULL [, ...]
* WHERE fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "UPDATE ONLY %s SET", fkrelname);
qualstr[0] = '\0';
querysep = "";
qualsep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
/*
* MATCH <unspecified> - only change columns corresponding
* to changed columns in pk_rel's key
*/
if (match_type == RI_MATCH_TYPE_FULL ||
!ri_OneKeyEqual(pk_rel, i, old_row, new_row, &qkey,
RI_KEYPAIR_PK_IDX))
{
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), "%s %s = NULL",
querysep, attname);
querysep = ",";
}
snprintf(qualstr + strlen(qualstr), sizeof(qualstr) - strlen(qualstr), " %s %s = $%d",
qualsep, attname, i + 1);
qualsep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, qualstr);
/*
* Prepare the plan. Save it only if we're building the
* "standard" plan.
*/
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel,
use_cached_query);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple old_row;
RI_QueryKey qkey;
void *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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 6) a) iii):
* MATCH <UNSPECIFIED> or MATCH FULL
* ... ON DELETE SET DEFAULT
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_SETNULL_DEL_DOUPDATE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No update - MATCH FULL means there cannot be any
* reference to old key if it contains 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");
/*
* Prepare a plan for the set default delete operation.
* Unfortunately we need to do it on every invocation because the
* default value could potentially change between calls.
*/
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS * 2];
char qualstr[(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
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 fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "UPDATE ONLY %s SET", fkrelname);
qualstr[0] = '\0';
querysep = "";
qualsep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), "%s %s = DEFAULT",
querysep, attname);
snprintf(qualstr + strlen(qualstr), sizeof(qualstr) - strlen(qualstr), " %s %s = $%d",
qualsep, attname, i + 1);
querysep = ",";
qualsep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, qualstr);
/* Prepare the plan, don't save it */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, false);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 null delete.
*/
case RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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;
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
void *qplan;
int match_type;
/*
* Check that this is a valid trigger call on the right time and event.
*/
ri_CheckTrigger(fcinfo, "RI_FKey_setdefault_upd", RI_TRIGTYPE_UPDATE);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
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(trigdata->tg_trigger->tgconstrrelid, RowExclusiveLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
switch (match_type)
{
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral rules 7) a) iii):
* MATCH <UNSPECIFIED> or MATCH FULL
* ... ON UPDATE SET DEFAULT
* ----------
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
RI_PLAN_SETNULL_DEL_DOUPDATE,
fk_rel, pk_rel,
tgnargs, tgargs);
switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
{
case RI_KEYS_ALL_NULL:
case RI_KEYS_SOME_NULL:
/*
* No update - MATCH FULL means there cannot be any
* reference to old key if it contains 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, &qkey,
RI_KEYPAIR_PK_IDX))
{
heap_close(fk_rel, RowExclusiveLock);
return PointerGetDatum(NULL);
}
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* Prepare a plan for the set default delete operation.
* Unfortunately we need to do it on every invocation because the
* default value could potentially change between calls.
*/
{
char querystr[MAX_QUOTED_REL_NAME_LEN + 100 +
(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS * 2];
char qualstr[(MAX_QUOTED_NAME_LEN + 32) * RI_MAX_NUMKEYS];
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
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 fkatt1 = $1 [AND ...]
* The type id's for the $ parameters are those of the
* corresponding PK attributes. Thus, ri_PlanCheck could
* eventually fail if the parser cannot identify some way
* how to compare these two types by '='.
* ----------
*/
quoteRelationName(fkrelname, fk_rel);
snprintf(querystr, sizeof(querystr), "UPDATE ONLY %s SET", fkrelname);
qualstr[0] = '\0';
querysep = "";
qualsep = "WHERE";
for (i = 0; i < qkey.nkeypairs; i++)
{
quoteOneName(attname,
tgargs[RI_FIRST_ATTNAME_ARGNO + i * 2 + RI_KEYPAIR_FK_IDX]);
/*
* MATCH <unspecified> - only change columns corresponding
* to changed columns in pk_rel's key
*/
if (match_type == RI_MATCH_TYPE_FULL ||
!ri_OneKeyEqual(pk_rel, i, old_row,
new_row, &qkey, RI_KEYPAIR_PK_IDX))
{
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr), "%s %s = DEFAULT",
querysep, attname);
querysep = ",";
}
snprintf(qualstr + strlen(qualstr), sizeof(qualstr) - strlen(qualstr), " %s %s = $%d",
qualsep, attname, i + 1);
qualsep = "AND";
queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
}
strcat(querystr, qualstr);
/* Prepare the plan, don't save it */
qplan = ri_PlanCheck(querystr, qkey.nkeypairs, queryoids,
&qkey, fk_rel, pk_rel, false);
}
/*
* We have a plan now. Run it to update the existing references.
*/
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
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 null delete.
*/
case RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
return PointerGetDatum(NULL);
}
/*
* Never reached
*/
elog(ERROR, "invalid match_type");
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)
{
int tgnargs;
char **tgargs;
Relation fk_rel;
RI_QueryKey qkey;
/*
* Check for the correct # of call arguments
*/
tgnargs = trigger->tgnargs;
tgargs = trigger->tgargs;
if (tgnargs < 4 ||
tgnargs > RI_MAX_ARGUMENTS ||
(tgnargs % 2) != 0)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" called with wrong number of trigger arguments",
"RI_FKey_keyequal_upd")));
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
return true;
if (!OidIsValid(trigger->tgconstrrelid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("no target table given for trigger \"%s\" on table \"%s\"",
trigger->tgname,
RelationGetRelationName(pk_rel)),
errhint("Remove this referential integrity trigger and its mates, "
"then do ALTER TABLE ADD CONSTRAINT.")));
fk_rel = heap_open(trigger->tgconstrrelid, AccessShareLock);
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigger->tgoid,
RI_PLAN_KEYEQUAL_UPD,
fk_rel, pk_rel,
tgnargs, tgargs);
heap_close(fk_rel, AccessShareLock);
/* Return if key's are equal */
return ri_KeysEqual(pk_rel, old_row, new_row, &qkey,
RI_KEYPAIR_PK_IDX);
/* Handle MATCH PARTIAL set null delete. */
case RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
}
/* Never reached */
elog(ERROR, "invalid match_type");
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)
{
int tgnargs;
char **tgargs;
Relation pk_rel;
RI_QueryKey qkey;
/*
* Check for the correct # of call arguments
*/
tgnargs = trigger->tgnargs;
tgargs = trigger->tgargs;
if (tgnargs < 4 ||
tgnargs > RI_MAX_ARGUMENTS ||
(tgnargs % 2) != 0)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" called with wrong number of trigger arguments",
"RI_FKey_keyequal_upd")));
/*
* Nothing to do if no column names to compare given
*/
if (tgnargs == 4)
return true;
if (!OidIsValid(trigger->tgconstrrelid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("no target table given for trigger \"%s\" on table \"%s\"",
trigger->tgname,
RelationGetRelationName(fk_rel)),
errhint("Remove this referential integrity trigger and its mates, "
"then do ALTER TABLE ADD CONSTRAINT.")));
pk_rel = heap_open(trigger->tgconstrrelid, AccessShareLock);
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigger->tgoid,
RI_PLAN_KEYEQUAL_UPD,
fk_rel, pk_rel,
tgnargs, tgargs);
heap_close(pk_rel, AccessShareLock);
/* Return if key's are equal */
return ri_KeysEqual(fk_rel, old_row, new_row, &qkey,
RI_KEYPAIR_FK_IDX);
/* Handle MATCH PARTIAL set null delete. */
case RI_MATCH_TYPE_PARTIAL:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("MATCH PARTIAL not yet implemented")));
break;
}
/* Never reached */
elog(ERROR, "invalid match_type");
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 an exclusive lock has been taken on rel and pkrel;
* 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(FkConstraint *fkconstraint, Relation rel, Relation pkrel)
{
const char *constrname = fkconstraint->constr_name;
char querystr[MAX_QUOTED_REL_NAME_LEN * 2 + 250 +
(MAX_QUOTED_NAME_LEN + 32) * ((RI_MAX_NUMKEYS * 4) + 1)];
char pkrelname[MAX_QUOTED_REL_NAME_LEN];
char relname[MAX_QUOTED_REL_NAME_LEN];
char attname[MAX_QUOTED_NAME_LEN];
char fkattname[MAX_QUOTED_NAME_LEN];
const char *sep;
ListCell *l;
ListCell *l2;
int old_work_mem;
char workmembuf[32];
int spi_result;
void *qplan;
/*
* 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?
*/
if (pg_class_aclcheck(RelationGetRelid(rel), GetUserId(), ACL_SELECT) != ACLCHECK_OK)
return false;
if (pg_class_aclcheck(RelationGetRelid(pkrel), GetUserId(), ACL_SELECT) != ACLCHECK_OK)
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 unspecified:
* (fk.keycol1 IS NOT NULL [AND ...])
* For MATCH FULL:
* (fk.keycol1 IS NOT NULL [OR ...])
*----------
*/
sprintf(querystr, "SELECT ");
sep = "";
foreach(l, fkconstraint->fk_attrs)
{
quoteOneName(attname, strVal(lfirst(l)));
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
"%sfk.%s", sep, attname);
sep = ", ";
}
quoteRelationName(pkrelname, pkrel);
quoteRelationName(relname, rel);
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
" FROM ONLY %s fk LEFT OUTER JOIN ONLY %s pk ON (",
relname, pkrelname);
sep = "";
forboth(l, fkconstraint->pk_attrs, l2, fkconstraint->fk_attrs)
{
quoteOneName(attname, strVal(lfirst(l)));
quoteOneName(fkattname, strVal(lfirst(l2)));
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
"%spk.%s=fk.%s",
sep, attname, fkattname);
sep = " AND ";
}
/*
* It's sufficient to test any one pk attribute for null to detect a join
* failure.
*/
quoteOneName(attname, strVal(linitial(fkconstraint->pk_attrs)));
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
") WHERE pk.%s IS NULL AND (", attname);
sep = "";
foreach(l, fkconstraint->fk_attrs)
{
quoteOneName(attname, strVal(lfirst(l)));
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
"%sfk.%s IS NOT NULL",
sep, attname);
switch (fkconstraint->fk_matchtype)
{
case FKCONSTR_MATCH_UNSPECIFIED:
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 match type: %d",
fkconstraint->fk_matchtype);
break;
}
}
snprintf(querystr + strlen(querystr), sizeof(querystr) - strlen(querystr),
")");
/*
* 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 do the equivalent of "SET LOCAL work_mem" so that transaction abort
* will restore the old value if we lose control due to an error.
*/
old_work_mem = work_mem;
snprintf(workmembuf, sizeof(workmembuf), "%d", maintenance_work_mem);
(void) set_config_option("work_mem", workmembuf,
PGC_USERSET, PGC_S_SESSION,
true, true);
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(querystr, 0, NULL);
if (qplan == NULL)
elog(ERROR, "SPI_prepare returned %d for %s", SPI_result, querystr);
/*
* Run the plan. For safety we force a current snapshot to be used. (In
* serializable mode, this arguably violates serializability, but we
* really haven't got much choice.) We need at most one tuple returned,
* so pass limit = 1.
*/
spi_result = SPI_execute_snapshot(qplan,
NULL, NULL,
CopySnapshot(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;
int nkeys = list_length(fkconstraint->fk_attrs);
int i;
RI_QueryKey qkey;
/*
* 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 (fkconstraint->fk_matchtype == FKCONSTR_MATCH_FULL)
{
bool isnull = false;
for (i = 1; i <= nkeys; i++)
{
(void) SPI_getbinval(tuple, tupdesc, i, &isnull);
if (isnull)
break;
}
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(rel),
constrname),
errdetail("MATCH FULL does not allow mixing of null and nonnull key values.")));
}
/*
* Although we didn't cache the query, we need to set up a fake query
* key to pass to ri_ReportViolation.
*/
MemSet(&qkey, 0, sizeof(qkey));
qkey.constr_queryno = RI_PLAN_CHECK_LOOKUPPK;
qkey.nkeypairs = nkeys;
for (i = 0; i < nkeys; i++)
qkey.keypair[i][RI_KEYPAIR_FK_IDX] = i + 1;
ri_ReportViolation(&qkey, constrname,
pkrel, rel,
tuple, tupdesc,
false);
}
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
/*
* Restore work_mem for the remainder of the current transaction. This is
* another SET LOCAL, so it won't affect the session value, nor any
* tentative value if there is one.
*/
snprintf(workmembuf, sizeof(workmembuf), "%d", old_work_mem);
(void) set_config_option("work_mem", workmembuf,
PGC_USERSET, PGC_S_SESSION,
true, true);
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_DetermineMatchType -
*
* Convert the MATCH TYPE string into a switchable int
* ----------
*/
static int
ri_DetermineMatchType(char *str)
{
if (strcmp(str, "UNSPECIFIED") == 0)
return RI_MATCH_TYPE_UNSPECIFIED;
if (strcmp(str, "FULL") == 0)
return RI_MATCH_TYPE_FULL;
if (strcmp(str, "PARTIAL") == 0)
return RI_MATCH_TYPE_PARTIAL;
elog(ERROR, "unrecognized referential integrity match type \"%s\"", str);
return 0;
}
/* ----------
* ri_BuildQueryKeyFull -
*
* Build up a new hashtable key for a prepared SPI plan of a
* constraint trigger of MATCH FULL. The key consists of:
*
* constr_type is FULL
* constr_id is the OID of the pg_trigger row that invoked us
* constr_queryno is an internal number of the query inside the proc
* fk_relid is the OID of referencing relation
* pk_relid is the OID of referenced relation
* nkeypairs is the number of keypairs
* following are the attribute number keypairs of the trigger invocation
*
* At least for MATCH FULL this builds a unique key per plan.
* ----------
*/
static void
ri_BuildQueryKeyFull(RI_QueryKey *key, Oid constr_id, int32 constr_queryno,
Relation fk_rel, Relation pk_rel,
int argc, char **argv)
{
int i;
int j;
int fno;
/*
* Initialize the key and fill in type, oid's and number of keypairs
*/
memset(key, 0, sizeof(RI_QueryKey));
key->constr_type = RI_MATCH_TYPE_FULL;
key->constr_id = constr_id;
key->constr_queryno = constr_queryno;
key->fk_relid = fk_rel->rd_id;
key->pk_relid = pk_rel->rd_id;
key->nkeypairs = (argc - RI_FIRST_ATTNAME_ARGNO) / 2;
/*
* Lookup the attribute numbers of the arguments to the trigger call and
* fill in the keypairs.
*/
for (i = 0, j = RI_FIRST_ATTNAME_ARGNO; j < argc; i++, j += 2)
{
fno = SPI_fnumber(fk_rel->rd_att, argv[j]);
if (fno == SPI_ERROR_NOATTRIBUTE)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("table \"%s\" does not have column \"%s\" referenced by constraint \"%s\"",
RelationGetRelationName(fk_rel),
argv[j],
argv[RI_CONSTRAINT_NAME_ARGNO])));
key->keypair[i][RI_KEYPAIR_FK_IDX] = fno;
fno = SPI_fnumber(pk_rel->rd_att, argv[j + 1]);
if (fno == SPI_ERROR_NOATTRIBUTE)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("table \"%s\" does not have column \"%s\" referenced by constraint \"%s\"",
RelationGetRelationName(pk_rel),
argv[j + 1],
argv[RI_CONSTRAINT_NAME_ARGNO])));
key->keypair[i][RI_KEYPAIR_PK_IDX] = fno;
}
}
/*
* 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;
int tgnargs;
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;
}
/*
* Check for the correct # of call arguments
*/
tgnargs = trigdata->tg_trigger->tgnargs;
if (tgnargs < 4 ||
tgnargs > RI_MAX_ARGUMENTS ||
(tgnargs % 2) != 0)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("function \"%s\" called with wrong number of trigger arguments",
funcname)));
/*
* Check that tgconstrrelid is known. We need to check here because of
* ancient pg_dump bug; see notes in CreateTrigger().
*/
if (!OidIsValid(trigdata->tg_trigger->tgconstrrelid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("no target table given for trigger \"%s\" on table \"%s\"",
trigdata->tg_trigger->tgname,
RelationGetRelationName(trigdata->tg_relation)),
errhint("Remove this referential integrity trigger and its mates, then do ALTER TABLE ADD CONSTRAINT.")));
}
/*
* 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 void *
ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
RI_QueryKey *qkey, Relation fk_rel, Relation pk_rel,
bool cache_plan)
{
void *qplan;
Relation query_rel;
Oid save_userid;
bool save_secdefcxt;
/*
* The query is always run against the FK table except when this is an
* update/insert trigger on the FK table itself - either
* RI_PLAN_CHECK_LOOKUPPK or RI_PLAN_CHECK_LOOKUPPK_NOCOLS
*/
if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK ||
qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK_NOCOLS)
query_rel = pk_rel;
else
query_rel = fk_rel;
/* Switch to proper UID to perform check as */
GetUserIdAndContext(&save_userid, &save_secdefcxt);
SetUserIdAndContext(RelationGetForm(query_rel)->relowner, true);
/* 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 */
SetUserIdAndContext(save_userid, save_secdefcxt);
/* Save the plan if requested */
if (cache_plan)
{
qplan = SPI_saveplan(qplan);
ri_HashPreparedPlan(qkey, qplan);
}
return qplan;
}
/*
* Perform a query to enforce an RI restriction
*/
static bool
ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows,
int expect_OK, const char *constrname)
{
Relation query_rel,
source_rel;
int key_idx;
Snapshot test_snapshot;
Snapshot crosscheck_snapshot;
int limit;
int spi_result;
Oid save_userid;
bool save_secdefcxt;
Datum vals[RI_MAX_NUMKEYS * 2];
char nulls[RI_MAX_NUMKEYS * 2];
/*
* The query is always run against the FK table except when this is an
* update/insert trigger on the FK table itself - either
* RI_PLAN_CHECK_LOOKUPPK or RI_PLAN_CHECK_LOOKUPPK_NOCOLS
*/
if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK ||
qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK_NOCOLS)
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 (the
* case when constrname == NULL)
*/
if (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK && constrname != NULL)
{
source_rel = fk_rel;
key_idx = RI_KEYPAIR_FK_IDX;
}
else
{
source_rel = pk_rel;
key_idx = RI_KEYPAIR_PK_IDX;
}
/* Extract the parameters to be passed into the query */
if (new_tuple)
{
ri_ExtractValues(qkey, key_idx, source_rel, new_tuple,
vals, nulls);
if (old_tuple)
ri_ExtractValues(qkey, key_idx, source_rel, old_tuple,
vals + qkey->nkeypairs, nulls + qkey->nkeypairs);
}
else
{
ri_ExtractValues(qkey, key_idx, source_rel, old_tuple,
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
* SERIALIZABLE 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.
*/
if (IsXactIsoLevelSerializable && detectNewRows)
{
CommandCounterIncrement(); /* be sure all my own work is visible */
test_snapshot = CopySnapshot(GetLatestSnapshot());
crosscheck_snapshot = CopySnapshot(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 */
GetUserIdAndContext(&save_userid, &save_secdefcxt);
SetUserIdAndContext(RelationGetForm(query_rel)->relowner, true);
/* Finally we can run the query. */
spi_result = SPI_execute_snapshot(qplan,
vals, nulls,
test_snapshot, crosscheck_snapshot,
false, false, limit);
/* Restore UID */
SetUserIdAndContext(save_userid, save_secdefcxt);
/* 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(qkey, constrname ? constrname : "",
pk_rel, fk_rel,
new_tuple ? new_tuple : old_tuple,
NULL,
true);
/* XXX wouldn't it be clearer to do this part at the caller? */
if (constrname && expect_OK == SPI_OK_SELECT &&
(SPI_processed == 0) == (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK))
ri_ReportViolation(qkey, constrname,
pk_rel, fk_rel,
new_tuple ? new_tuple : old_tuple,
NULL,
false);
return SPI_processed != 0;
}
/*
* Extract fields from a tuple into Datum/nulls arrays
*/
static void
ri_ExtractValues(RI_QueryKey *qkey, int key_idx,
Relation rel, HeapTuple tuple,
Datum *vals, char *nulls)
{
int i;
bool isnull;
for (i = 0; i < qkey->nkeypairs; i++)
{
vals[i] = SPI_getbinval(tuple, rel->rd_att,
qkey->keypair[i][key_idx],
&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(RI_QueryKey *qkey, const char *constrname,
Relation pk_rel, Relation fk_rel,
HeapTuple violator, TupleDesc tupdesc,
bool spi_err)
{
#define BUFLENGTH 512
char key_names[BUFLENGTH];
char key_values[BUFLENGTH];
char *name_ptr = key_names;
char *val_ptr = key_values;
bool onfk;
int idx,
key_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),
constrname,
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 = (qkey->constr_queryno == RI_PLAN_CHECK_LOOKUPPK);
if (onfk)
{
key_idx = RI_KEYPAIR_FK_IDX;
if (tupdesc == NULL)
tupdesc = fk_rel->rd_att;
}
else
{
key_idx = RI_KEYPAIR_PK_IDX;
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 (qkey->nkeypairs == 0)
{
ereport(ERROR,
(errcode(ERRCODE_FOREIGN_KEY_VIOLATION),
errmsg("insert or update on table \"%s\" violates foreign key constraint \"%s\"",
RelationGetRelationName(fk_rel), constrname),
errdetail("No rows were found in \"%s\".",
RelationGetRelationName(pk_rel))));
}
/* Get printable versions of the keys involved */
for (idx = 0; idx < qkey->nkeypairs; idx++)
{
int fnum = qkey->keypair[idx][key_idx];
char *name,
*val;
name = SPI_fname(tupdesc, fnum);
val = SPI_getvalue(violator, tupdesc, fnum);
if (!val)
val = "null";
/*
* Go to "..." if name or value doesn't fit in buffer. We reserve 5
* bytes to ensure we can add comma, "...", null.
*/
if (strlen(name) >= (key_names + BUFLENGTH - 5) - name_ptr ||
strlen(val) >= (key_values + BUFLENGTH - 5) - val_ptr)
{
sprintf(name_ptr, "...");
sprintf(val_ptr, "...");
break;
}
name_ptr += sprintf(name_ptr, "%s%s", idx > 0 ? "," : "", name);
val_ptr += sprintf(val_ptr, "%s%s", idx > 0 ? "," : "", 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), constrname),
errdetail("Key (%s)=(%s) is not present in table \"%s\".",
key_names, key_values,
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),
constrname, RelationGetRelationName(fk_rel)),
errdetail("Key (%s)=(%s) is still referenced from table \"%s\".",
key_names, key_values,
RelationGetRelationName(fk_rel))));
}
/* ----------
* ri_BuildQueryKeyPkCheck -
*
* Build up a new hashtable key for a prepared SPI plan of a
* check for PK rows in noaction triggers.
*
* constr_type is FULL
* constr_id is the OID of the pg_trigger row that invoked us
* constr_queryno is an internal number of the query inside the proc
* pk_relid is the OID of referenced relation
* nkeypairs is the number of keypairs
* following are the attribute number keypairs of the trigger invocation
*
* At least for MATCH FULL this builds a unique key per plan.
* ----------
*/
static void
ri_BuildQueryKeyPkCheck(RI_QueryKey *key, Oid constr_id, int32 constr_queryno,
Relation pk_rel,
int argc, char **argv)
{
int i;
int j;
int fno;
/*
* Initialize the key and fill in type, oid's and number of keypairs
*/
memset((void *) key, 0, sizeof(RI_QueryKey));
key->constr_type = RI_MATCH_TYPE_FULL;
key->constr_id = constr_id;
key->constr_queryno = constr_queryno;
key->fk_relid = 0;
key->pk_relid = pk_rel->rd_id;
key->nkeypairs = (argc - RI_FIRST_ATTNAME_ARGNO) / 2;
/*
* Lookup the attribute numbers of the arguments to the trigger call and
* fill in the keypairs.
*/
for (i = 0, j = RI_FIRST_ATTNAME_ARGNO + RI_KEYPAIR_PK_IDX; j < argc; i++, j += 2)
{
fno = SPI_fnumber(pk_rel->rd_att, argv[j]);
if (fno == SPI_ERROR_NOATTRIBUTE)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("table \"%s\" does not have column \"%s\" referenced by constraint \"%s\"",
RelationGetRelationName(pk_rel),
argv[j],
argv[RI_CONSTRAINT_NAME_ARGNO])));
key->keypair[i][RI_KEYPAIR_PK_IDX] = fno;
key->keypair[i][RI_KEYPAIR_FK_IDX] = 0;
}
}
/* ----------
* 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(Relation rel, HeapTuple tup, RI_QueryKey *key, int pairidx)
{
int i;
bool isnull;
bool allnull = true;
bool nonenull = true;
for (i = 0; i < key->nkeypairs; i++)
{
isnull = false;
SPI_getbinval(tup, rel->rd_att, key->keypair[i][pairidx], &isnull);
if (isnull)
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 table for prepared
* query plans.
* ----------
*/
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);
}
/* ----------
* 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 void *
ri_FetchPreparedPlan(RI_QueryKey *key)
{
RI_QueryHashEntry *entry;
/*
* 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;
return entry->plan;
}
/* ----------
* ri_HashPreparedPlan -
*
* Add another plan to our private SPI query plan hashtable.
* ----------
*/
static void
ri_HashPreparedPlan(RI_QueryKey *key, void *plan)
{
RI_QueryHashEntry *entry;
bool found;
/*
* On the first call initialize the hashtable
*/
if (!ri_query_cache)
ri_InitHashTables();
/*
* Add the new plan.
*/
entry = (RI_QueryHashEntry *) hash_search(ri_query_cache,
(void *) key,
HASH_ENTER, &found);
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,
RI_QueryKey *key, int pairidx)
{
int i;
Oid typeid;
Datum oldvalue;
Datum newvalue;
bool isnull;
for (i = 0; i < key->nkeypairs; i++)
{
/*
* Get one attribute's oldvalue. If it is NULL - they're not equal.
*/
oldvalue = SPI_getbinval(oldtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
return false;
/*
* Get one attribute's oldvalue. If it is NULL - they're not equal.
*/
newvalue = SPI_getbinval(newtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
return false;
/*
* Get the attribute's type OID and call the '=' operator to compare
* the values.
*/
typeid = SPI_gettypeid(rel->rd_att, key->keypair[i][pairidx]);
if (!ri_AttributesEqual(typeid, oldvalue, newvalue))
return false;
}
return true;
}
/* ----------
* ri_AllKeysUnequal -
*
* Check if all key values in OLD and NEW are not equal.
* ----------
*/
static bool
ri_AllKeysUnequal(Relation rel, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx)
{
int i;
Oid typeid;
Datum oldvalue;
Datum newvalue;
bool isnull;
bool keys_unequal;
keys_unequal = true;
for (i = 0; keys_unequal && i < key->nkeypairs; i++)
{
/*
* Get one attributes oldvalue. If it is NULL - they're not equal.
*/
oldvalue = SPI_getbinval(oldtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
continue;
/*
* Get one attributes oldvalue. If it is NULL - they're not equal.
*/
newvalue = SPI_getbinval(newtup, rel->rd_att,
key->keypair[i][pairidx], &isnull);
if (isnull)
continue;
/*
* Get the attributes type OID and call the '=' operator to compare
* the values.
*/
typeid = SPI_gettypeid(rel->rd_att, key->keypair[i][pairidx]);
if (!ri_AttributesEqual(typeid, oldvalue, newvalue))
continue;
keys_unequal = false;
}
return keys_unequal;
}
/* ----------
* ri_OneKeyEqual -
*
* Check if one key value in OLD and NEW is equal.
*
* ri_KeysEqual could call this but would run a bit slower. For
* now, let's duplicate the code.
* ----------
*/
static bool
ri_OneKeyEqual(Relation rel, int column, HeapTuple oldtup, HeapTuple newtup,
RI_QueryKey *key, int pairidx)
{
Oid typeid;
Datum oldvalue;
Datum newvalue;
bool isnull;
/*
* Get one attributes oldvalue. If it is NULL - they're not equal.
*/
oldvalue = SPI_getbinval(oldtup, rel->rd_att,
key->keypair[column][pairidx], &isnull);
if (isnull)
return false;
/*
* Get one attributes oldvalue. If it is NULL - they're not equal.
*/
newvalue = SPI_getbinval(newtup, rel->rd_att,
key->keypair[column][pairidx], &isnull);
if (isnull)
return false;
/*
* Get the attributes type OID and call the '=' operator to compare the
* values.
*/
typeid = SPI_gettypeid(rel->rd_att, key->keypair[column][pairidx]);
if (!ri_AttributesEqual(typeid, oldvalue, newvalue))
return false;
return true;
}
/* ----------
* ri_AttributesEqual -
*
* Call the type specific '=' operator comparison function
* for two values.
*
* NB: we have already checked that neither value is null.
* ----------
*/
static bool
ri_AttributesEqual(Oid typeid, Datum oldvalue, Datum newvalue)
{
TypeCacheEntry *typentry;
/*
* Find the data type in the typcache, and ask for eq_opr info.
*/
typentry = lookup_type_cache(typeid, TYPECACHE_EQ_OPR_FINFO);
if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("could not identify an equality operator for type %s",
format_type_be(typeid))));
/*
* Call the type specific '=' function
*/
return DatumGetBool(FunctionCall2(&(typentry->eq_opr_finfo),
oldvalue, newvalue));
}
/*
* 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;
}
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