rdelaage/postgresql
1
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2024-08-20 17:33:23 +02:00
Code Issues Packages Projects Releases Wiki Activity
d0b4399d81
postgresql/src/backend/utils/adt/ri_triggers.c
Neil Conway d0b4399d81 Reimplement the linked list data structure used throughout the backend. 
In the past, we used a 'Lispy' linked list implementation: a "list" was
merely a pointer to the head node of the list. The problem with that
design is that it makes lappend() and length() linear time. This patch
fixes that problem (and others) by maintaining a count of the list
length and a pointer to the tail node along with each head node pointer.
A "list" is now a pointer to a structure containing some meta-data
about the list; the head and tail pointers in that structure refer
to ListCell structures that maintain the actual linked list of nodes.

The function names of the list API have also been changed to, I hope,
be more logically consistent. By default, the old function names are
still available; they will be disabled-by-default once the rest of
the tree has been updated to use the new API names.
2004-05-26 04:41:50 +00:00

3638 lines
97 KiB
C
Raw Blame History

/* ----------
* ri_triggers.c
*
* Generic trigger procedures for referential integrity constraint
* checks.
*
* Note about memory management: the private hashtables kept here live
* across query and transaction boundaries, in fact they live as long as
* the backend does. This works because the hashtable structures
* themselves are allocated by dynahash.c in its permanent DynaHashCxt,
* and the 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) 1996-2003, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.68 2004/05/26 04:41:38 neilc Exp $
*
* ----------
*/
/* ----------
* Internal TODO:
*
* Add MATCH PARTIAL logic.
* ----------
*/
#include "postgres.h"
#include "catalog/pg_operator.h"
#include "commands/trigger.h"
#include "executor/spi_priv.h"
#include "optimizer/planmain.h"
#include "parser/parse_oper.h"
#include "rewrite/rewriteHandler.h"
#include "utils/lsyscache.h"
#include "utils/typcache.h"
#include "utils/acl.h"
#include "utils/guc.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;
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);
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_trigger->tgargs;
/*
* Get the relation descriptors of the FK and PK tables and the new
* tuple.
*
* pk_rel is opened in RowShareLock mode since that's what our eventual
* SELECT FOR UPDATE will get on it.
*/
pk_rel = heap_open(trigdata->tg_trigger->tgconstrrelid, RowShareLock);
fk_rel = trigdata->tg_relation;
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
old_row = trigdata->tg_trigtuple;
new_row = trigdata->tg_newtuple;
}
else
{
old_row = NULL;
new_row = trigdata->tg_trigtuple;
}
/*
* We should not even consider checking the row if it is no longer
* valid since it was either deleted (doesn't matter) or updated (in
* which case it'll be checked with its final values).
*/
if (new_row)
{
if (!HeapTupleSatisfiesItself(new_row->t_data))
{
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
}
/* ----------
* SQL3 11.9 <referential constraint definition>
* Gereral 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 UPDATE 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;
}
/*
* No need to check anything if old and new references are the same on
* UPDATE.
*/
if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
{
if (HeapTupleHeaderGetXmin(old_row->t_data) !=
GetCurrentTransactionId() &&
ri_KeysEqual(fk_rel, old_row, new_row, &qkey,
RI_KEYPAIR_FK_IDX))
{
heap_close(pk_rel, RowShareLock);
return PointerGetDatum(NULL);
}
}
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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 UPDATE 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 -
*
* Check if we have a key change on update.
*
* This is not a real trigger procedure. It is used by the deferred
* trigger queue manager to detect "triggered data change violation".
* ----------
*/
bool
RI_FKey_keyequal_upd(TriggerData *trigdata)
{
int tgnargs;
char **tgargs;
Relation fk_rel;
Relation pk_rel;
HeapTuple new_row;
HeapTuple old_row;
RI_QueryKey qkey;
/*
* Check for the correct # of call arguments
*/
tgnargs = trigdata->tg_trigger->tgnargs;
tgargs = trigdata->tg_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;
/*
* Get the relation descriptors of the FK and PK tables and the new
* and old tuple.
*
* Use minimal locking for fk_rel here.
*/
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.")));
fk_rel = heap_open(trigdata->tg_trigger->tgconstrrelid, AccessShareLock);
pk_rel = trigdata->tg_relation;
new_row = trigdata->tg_newtuple;
old_row = trigdata->tg_trigtuple;
switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
{
/*
* MATCH <UNSPECIFIED>
*/
case RI_MATCH_TYPE_UNSPECIFIED:
case RI_MATCH_TYPE_FULL:
ri_BuildQueryKeyFull(&qkey, trigdata->tg_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_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 query 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_execp_current(qplan, NULL, NULL, true, 1);
/* Check result */
if (spi_result != SPI_OK_SELECT)
elog(ERROR, "SPI_execp_current 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 = 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((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 = 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;
AclId save_uid;
/*
* 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 */
save_uid = GetUserId();
SetUserId(RelationGetForm(query_rel)->relowner);
/* 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 */
SetUserId(save_uid);
/* 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;
bool useCurrentSnapshot;
int limit;
int spi_result;
AclId save_uid;
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 make sure the regular query
* snapshot is up-to-date, and we will see all rows that could be
* interesting. In SERIALIZABLE mode, we can't update the regular query
* snapshot. If the caller passes detectNewRows == false then it's okay
* to do the query with the transaction snapshot; otherwise we tell the
* executor to force a current snapshot (and error out if it finds any
* rows under current snapshot that wouldn't be visible per the
* transaction snapshot).
*/
if (IsXactIsoLevelSerializable)
{
useCurrentSnapshot = detectNewRows;
}
else
{
SetQuerySnapshot();
useCurrentSnapshot = false;
}
/*
* 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 */
save_uid = GetUserId();
SetUserId(RelationGetForm(query_rel)->relowner);
/* Finally we can run the query. */
spi_result = SPI_execp_current(qplan, vals, nulls,
useCurrentSnapshot, limit);
/* Restore UID */
SetUserId(save_uid);
/* Check result */
if (spi_result < 0)
elog(ERROR, "SPI_execp_current 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 \"%s\" violates foreign key constraint \"%s\" on \"%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);
if (entry == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
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 attributes 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 attributes 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 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))
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));
}
Reference in New Issue View Git Blame Copy Permalink