Hi All,
I've changed the check_primary_key() function code to allow for either
the "automatic insert key rule" or "dependent insert key rule".
Previously it restricted the addtion of a child entry if the
corresponding parent entry was not there. Now if the option is
"automatic" it will add an entry in the parent too ( it will be
successful if there are no no-null fields in the parent apart from the
primary key).
The way to use it now is:
/*
 * check_primary_key () -- check that key in tuple being
inserted/updated
 *                       references existing tuple in "primary" table.
 * Though it's called without args You have to specify referenced
 * table/keys while creating trigger:  key field names in triggered
table,
 * referenced table name, referenced key field names,type of action
[automatic|dependent]:
 * EXECUTE PROCEDURE
 * check_primary_key ('Fkey1', 'Fkey2', 'Ptable', 'Pkey1', 'Pkey2',
'[automatic|dependent]').
 */
I am attaching the new ../contrib/spi/refint.c file which will do this.
I will be glad to help in case of any problems.

- Anand.
Mon, 21 Sep 1998 12:05:52 -0700
Anand Surelia <anand@bytekinc.com>
Foreign Keys: check_primary_function
Applied.


> Hi All,
> I've changed the check_primary_key() function code to allow for either
> the "automatic insert key rule" or "dependent insert key rule".
> Previously it restricted the addtion of a child entry if the
> corresponding parent entry was not there. Now if the option is
> "automatic" it will add an entry in the parent too ( it will be
> successful if there are no no-null fields in the parent apart from the
> primary key).
> The way to use it now is:
> /*
>  * check_primary_key () -- check that key in tuple being
> inserted/updated
>  *                       references existing tuple in "primary" table.
>  * Though it's called without args You have to specify referenced
>  * table/keys while creating trigger:  key field names in triggered
> table,
>  * referenced table name, referenced key field names,type of action
> [automatic|dependent]:
>  * EXECUTE PROCEDURE
>  * check_primary_key ('Fkey1', 'Fkey2', 'Ptable', 'Pkey1', 'Pkey2',
> '[automatic|dependent]').
>  */
> I am attaching the new ../contrib/spi/refint.c file which will do this.
> I will be glad to help in case of any problems.
> 
> - Anand.
> 
> 

> /*
>  * refint.c --	set of functions to define referential integrity
>  *		constraints using general triggers.
>  */
> 
> #include "executor/spi.h"		/* this is what you need to work with SPI */
> #include "commands/trigger.h"	/* -"- and triggers */
> #include <ctype.h>				/* tolower () */
> 
> HeapTuple	check_primary_key(void);
> HeapTuple	check_foreign_key(void);
> 
> 
> typedef struct
> {
> 	char	   *ident;
> 	int			nplans;
> 	void	  **splan;
> }			EPlan;
> 
> static EPlan *FPlans = NULL;
> static int	nFPlans = 0;
> static EPlan *PPlans = NULL;
> static int	nPPlans = 0;
> 
> static EPlan *find_plan(char *ident, EPlan ** eplan, int *nplans);
> 
> /*
>  * check_primary_key () -- check that key in tuple being inserted/updated
>  *			 references existing tuple in "primary" table.
>  * Though it's called without args You have to specify referenced
>  * table/keys while creating trigger:  key field names in triggered table,
>  * referenced table name, referenced key field names,type of action [automatic|dependent]:
>  * EXECUTE PROCEDURE
>  * check_primary_key ('Fkey1', 'Fkey2', 'Ptable', 'Pkey1', 'Pkey2','[automatic|dependent]').
>  */
> 
> HeapTuple						/* have to return HeapTuple to Executor */
> check_primary_key()
> {
> 	Trigger    *trigger;		/* to get trigger name */
> 	int			nargs;			/* # of args specified in CREATE TRIGGER */
> 	char	  **args;			/* arguments: column names and table name */
> 	int			nkeys;			/* # of key columns (= (nargs-1) / 2) */
> 	Datum	   *kvals;			/* key values */
> 	char	   *relname;		/* referenced relation name */
> 	char	   *action;             /* action on insert or update*/
> 	Relation	rel;			/* triggered relation */
> 	HeapTuple	tuple = NULL;	/* tuple to return */
> 	TupleDesc	tupdesc;		/* tuple description */
> 	EPlan	   *plan;			/* prepared plan */
> 	Oid		   *argtypes = NULL;/* key types to prepare execution plan */
> 	bool		isnull;			/* to know is some column NULL or not */
> 	char		ident[2 * NAMEDATALEN]; /* to identify myself */
> 	int			ret;
> 	int			i;
> 
> 	/*
> 	 * Some checks first...
> 	 */
> 
> 	/* Called by trigger manager ? */
> 	if (!CurrentTriggerData)
> 		elog(ERROR, "check_primary_key: triggers are not initialized");
> 
> 	/* Should be called for ROW trigger */
> 	if (TRIGGER_FIRED_FOR_STATEMENT(CurrentTriggerData->tg_event))
> 		elog(ERROR, "check_primary_key: can't process STATEMENT events");
> 
> 	/* If INSERTion then must check Tuple to being inserted */
> 	if (TRIGGER_FIRED_BY_INSERT(CurrentTriggerData->tg_event))
> 
> 		tuple = CurrentTriggerData->tg_trigtuple;
> 
> 	/* Not should be called for DELETE */
> 	else if (TRIGGER_FIRED_BY_DELETE(CurrentTriggerData->tg_event))
> 
> 		elog(ERROR, "check_primary_key: can't process DELETE events");
> 
> 	/* If UPDATion the must check new Tuple, not old one */
> 	else
> 		tuple = CurrentTriggerData->tg_newtuple;
> 
> 	trigger = CurrentTriggerData->tg_trigger;
> 	nargs = trigger->tgnargs;
> 	args = trigger->tgargs;
> 
> 	if ((nargs-1) % 2 != 1)			/* odd number of arguments! */
> 		elog(ERROR, "check_primary_key: even number of arguments should be specified");
> 
> 	nkeys = (nargs-1) / 2;
> 	action=args[nargs -1];
> 	if (strcmp(action,"automatic") && strcmp(action,"dependent"))
> 		elog(ERROR,"check_primary_key: unknown action");
> 	nargs=nargs-1;
> 	relname = args[nkeys];
> 	rel = CurrentTriggerData->tg_relation;
> 	tupdesc = rel->rd_att;
> 
> 	/*
> 	 * Setting CurrentTriggerData to NULL prevents direct calls to trigger
> 	 * functions in queries. Normally, trigger functions have to be called
> 	 * by trigger manager code only.
> 	 */
> 	CurrentTriggerData = NULL;
> 
> 	/* Connect to SPI manager */
> 	if ((ret = SPI_connect()) < 0)
> 		elog(ERROR, "check_primary_key: SPI_connect returned %d", ret);
> 
> 	/*
> 	 * We use SPI plan preparation feature, so allocate space to place key
> 	 * values.
> 	 */
> 	kvals = (Datum *) palloc(nkeys * sizeof(Datum));
> 
> 	/*
> 	 * Construct ident string as TriggerName $ TriggeredRelationId and try
> 	 * to find prepared execution plan.
> 	 */
> 	sprintf(ident, "%s$%u", trigger->tgname, rel->rd_id);
> 	plan = find_plan(ident, &PPlans, &nPPlans);
> 
> 	/* if there is no plan then allocate argtypes for preparation */
> 	if (plan->nplans <= 0)
> 		argtypes = (Oid *) palloc(nkeys * sizeof(Oid));
> 
> 	/* For each column in key ... */
> 	for (i = 0; i < nkeys; i++)
> 	{
> 		/* get index of column in tuple */
> 		int			fnumber = SPI_fnumber(tupdesc, args[i]);
> 
> 		/* Bad guys may give us un-existing column in CREATE TRIGGER */
> 		if (fnumber < 0)
> 			elog(ERROR, "check_primary_key: there is no attribute %s in relation %s",
> 				 args[i], SPI_getrelname(rel));
> 
> 		/* Well, get binary (in internal format) value of column */
> 		kvals[i] = SPI_getbinval(tuple, tupdesc, fnumber, &isnull);
> 
> 		/*
> 		 * If it's NULL then nothing to do! DON'T FORGET call SPI_finish
> 		 * ()! DON'T FORGET return tuple! Executor inserts tuple you're
> 		 * returning! If you return NULL then nothing will be inserted!
> 		 */
> 		if (isnull)
> 		{
> 			SPI_finish();
> 			return (tuple);
> 		}
> 
> 		if (plan->nplans <= 0)	/* Get typeId of column */
> 			argtypes[i] = SPI_gettypeid(tupdesc, fnumber);
> 	}
> 
> 	/*
> 	 * If we have to prepare plan ...
> 	 */
> 	if (plan->nplans <= 0)
> 	{
> 		void	   *pplan;
> 		char		sql[8192];
> 
> 		/*
> 		 * Construct query: SELECT 1 FROM _referenced_relation_ WHERE
> 		 * Pkey1 = $1 [AND Pkey2 = $2 [...]]
> 		 */
> 		sprintf(sql, "select 1 from %s where ", relname);
> 		for (i = 0; i < nkeys; i++)
> 		{
> 			sprintf(sql + strlen(sql), "%s = $%d %s",
> 			  args[i + nkeys + 1], i + 1, (i < nkeys - 1) ? "and " : "");
> 		}
> 
> 		/* Prepare plan for query */
> 		pplan = SPI_prepare(sql, nkeys, argtypes);
> 		if (pplan == NULL)
> 			elog(ERROR, "check_primary_key: SPI_prepare returned %d", SPI_result);
> 
> 		/*
> 		 * Remember that SPI_prepare places plan in current memory context
> 		 * - so, we have to save plan in Top memory context for latter
> 		 * use.
> 		 */
> 		pplan = SPI_saveplan(pplan);
> 		if (pplan == NULL)
> 			elog(ERROR, "check_primary_key: SPI_saveplan returned %d", SPI_result);
> 		plan->splan = (void **) malloc(sizeof(void *));
> 		*(plan->splan) = pplan;
> 		plan->nplans = 1;
> 	}
> 
> 	/*
> 	 * Ok, execute prepared plan.
> 	 */
> 	ret = SPI_execp(*(plan->splan), kvals, NULL, 1);
> 	/* we have no NULLs - so we pass   ^^^^   here */
> 
> 	if (ret < 0)
> 		elog(ERROR, "check_primary_key: SPI_execp returned %d", ret);
> 
> 	/*
> 	 * If there are no tuples returned by SELECT then ...
> 	 */
> 	if (SPI_processed == 0 && strcmp(action,"dependent")==0)
> 		elog(ERROR, "%s: tuple references non-existing key in %s",
> 			 trigger->tgname, relname);
> 	else if (strcmp(action,"automatic")==0) 
> 	{
> 		/* insert tuple in parent with only primary keys */
> 		/* prepare plan */
> 		void	   *pplan;
> 		char		sql[8192];
> 
> 		/*
> 		 * Construct query:INSERT INTO relname (Pkey1[,Pkey2]*) values ($1,$2..); 
> 		 */
> 		sprintf(sql, "insert into %s ( ", relname);
> 		for (i = 0; i < nkeys; i++)
> 		{
> 			sprintf(sql + strlen(sql), "%s%s ", args[i + nkeys + 1],(i<nkeys-1) ? ",":"");
> 		}
> 		sprintf(sql+strlen(sql),") values (");
> 		for (i=0;i<nkeys; i++)
> 		{
> 			sprintf(sql+strlen(sql),"$%d%s ",i+1,(i<nkeys-1) ? ",":"");
> 		} 
> 		sprintf(sql+strlen(sql),")");
> 
> 		/* Prepare plan for query */
> 		pplan = SPI_prepare(sql, nkeys, argtypes);
> 		if (pplan == NULL)
> 			elog(ERROR, "check_primary_key: SPI_prepare returned %d", SPI_result);
> 
> 		/*
> 		 * Remember that SPI_prepare places plan in current memory context
> 		 * - so, we have to save plan in Top memory context for latter
> 		 * use.
> 		 */
> 		pplan = SPI_saveplan(pplan);
> 		if (pplan == NULL)
> 			elog(ERROR, "check_primary_key: SPI_saveplan returned %d", SPI_result);
> 		plan->splan = (void **) malloc(sizeof(void *));
> 		*(plan->splan) = pplan;
> 		plan->nplans = 1;
> 	/*
> 	 * Ok, execute prepared plan.
> 	 */
> 	ret = SPI_execp(*(plan->splan), kvals, NULL, 1);
> 	/* we have no NULLs - so we pass   ^^^^   here */
> 
> 	if (ret < 0)
> 		elog(ERROR, "check_primary_key: SPI_execp returned %d", ret);
> 
> 	/*
> 	 * If there are no tuples returned by INSERT then ...
> 	 */
> 	if (SPI_processed == 0)
> 		elog(ERROR, "error: can't enter automatically in %s",relname);
> 	}
> 
> 	SPI_finish();
> 
> 	return (tuple);
> }
> 
> /*
>  * check_foreign_key () -- check that key in tuple being deleted/updated
>  *			 is not referenced by tuples in "foreign" table(s).
>  * Though it's called without args You have to specify (while creating trigger):
>  * number of references, action to do if key referenced
>  * ('restrict' | 'setnull' | 'cascade'), key field names in triggered
>  * ("primary") table and referencing table(s)/keys:
>  * EXECUTE PROCEDURE
>  * check_foreign_key (2, 'restrict', 'Pkey1', 'Pkey2',
>  * 'Ftable1', 'Fkey11', 'Fkey12', 'Ftable2', 'Fkey21', 'Fkey22').
>  */
> 
> HeapTuple						/* have to return HeapTuple to Executor */
> check_foreign_key()
> {
> 	Trigger    *trigger;		/* to get trigger name */
> 	int			nargs;			/* # of args specified in CREATE TRIGGER */
> 	char	  **args;			/* arguments: as described above */
> 	int			nrefs;			/* number of references (== # of plans) */
> 	char		action;			/* 'R'estrict | 'S'etnull | 'C'ascade */
> 	int			nkeys;			/* # of key columns */
> 	Datum	   *kvals;			/* key values */
> 	char	   *relname;		/* referencing relation name */
> 	Relation	rel;			/* triggered relation */
> 	HeapTuple	trigtuple = NULL;		/* tuple to being changed */
> 	HeapTuple	newtuple = NULL;/* tuple to return */
> 	TupleDesc	tupdesc;		/* tuple description */
> 	EPlan	   *plan;			/* prepared plan(s) */
> 	Oid		   *argtypes = NULL;/* key types to prepare execution plan */
> 	bool		isnull;			/* to know is some column NULL or not */
> 	bool		isequal = true; /* are keys in both tuples equal (in
> 								 * UPDATE) */
> 	char		ident[2 * NAMEDATALEN]; /* to identify myself */
> 	int			ret;
> 	int			i,
> 				r;
> 
> 	/*
> 	 * Some checks first...
> 	 */
> 
> 	/* Called by trigger manager ? */
> 	if (!CurrentTriggerData)
> 		elog(ERROR, "check_foreign_key: triggers are not initialized");
> 
> 	/* Should be called for ROW trigger */
> 	if (TRIGGER_FIRED_FOR_STATEMENT(CurrentTriggerData->tg_event))
> 		elog(ERROR, "check_foreign_key: can't process STATEMENT events");
> 
> 	/* Not should be called for INSERT */
> 	if (TRIGGER_FIRED_BY_INSERT(CurrentTriggerData->tg_event))
> 
> 		elog(ERROR, "check_foreign_key: can't process INSERT events");
> 
> 	/* Have to check tg_trigtuple - tuple being deleted */
> 	trigtuple = CurrentTriggerData->tg_trigtuple;
> 
> 	/*
> 	 * But if this is UPDATE then we have to return tg_newtuple. Also, if
> 	 * key in tg_newtuple is the same as in tg_trigtuple then nothing to
> 	 * do.
> 	 */
> 	if (TRIGGER_FIRED_BY_UPDATE(CurrentTriggerData->tg_event))
> 		newtuple = CurrentTriggerData->tg_newtuple;
> 
> 	trigger = CurrentTriggerData->tg_trigger;
> 	nargs = trigger->tgnargs;
> 	args = trigger->tgargs;
> 
> 	if (nargs < 5)				/* nrefs, action, key, Relation, key - at
> 								 * least */
> 		elog(ERROR, "check_foreign_key: too short %d (< 5) list of arguments", nargs);
> 	nrefs = pg_atoi(args[0], sizeof(int), 0);
> 	if (nrefs < 1)
> 		elog(ERROR, "check_foreign_key: %d (< 1) number of references specified", nrefs);
> 	action = tolower(*(args[1]));
> 	if (action != 'r' && action != 'c' && action != 's')
> 		elog(ERROR, "check_foreign_key: invalid action %s", args[1]);
> 	nargs -= 2;
> 	args += 2;
> 	nkeys = (nargs - nrefs) / (nrefs + 1);
> 	if (nkeys <= 0 || nargs != (nrefs + nkeys * (nrefs + 1)))
> 		elog(ERROR, "check_foreign_key: invalid number of arguments %d for %d references",
> 			 nargs + 2, nrefs);
> 
> 	rel = CurrentTriggerData->tg_relation;
> 	tupdesc = rel->rd_att;
> 
> 	/*
> 	 * Setting CurrentTriggerData to NULL prevents direct calls to trigger
> 	 * functions in queries. Normally, trigger functions have to be called
> 	 * by trigger manager code only.
> 	 */
> 	CurrentTriggerData = NULL;
> 
> 	/* Connect to SPI manager */
> 	if ((ret = SPI_connect()) < 0)
> 		elog(ERROR, "check_foreign_key: SPI_connect returned %d", ret);
> 
> 	/*
> 	 * We use SPI plan preparation feature, so allocate space to place key
> 	 * values.
> 	 */
> 	kvals = (Datum *) palloc(nkeys * sizeof(Datum));
> 
> 	/*
> 	 * Construct ident string as TriggerName $ TriggeredRelationId and try
> 	 * to find prepared execution plan(s).
> 	 */
> 	sprintf(ident, "%s$%u", trigger->tgname, rel->rd_id);
> 	plan = find_plan(ident, &FPlans, &nFPlans);
> 
> 	/* if there is no plan(s) then allocate argtypes for preparation */
> 	if (plan->nplans <= 0)
> 		argtypes = (Oid *) palloc(nkeys * sizeof(Oid));
> 
> 	/*
> 	 * else - check that we have exactly nrefs plan(s) ready
> 	 */
> 	else if (plan->nplans != nrefs)
> 		elog(ERROR, "%s: check_foreign_key: # of plans changed in meantime",
> 			 trigger->tgname);
> 
> 	/* For each column in key ... */
> 	for (i = 0; i < nkeys; i++)
> 	{
> 		/* get index of column in tuple */
> 		int			fnumber = SPI_fnumber(tupdesc, args[i]);
> 
> 		/* Bad guys may give us un-existing column in CREATE TRIGGER */
> 		if (fnumber < 0)
> 			elog(ERROR, "check_foreign_key: there is no attribute %s in relation %s",
> 				 args[i], SPI_getrelname(rel));
> 
> 		/* Well, get binary (in internal format) value of column */
> 		kvals[i] = SPI_getbinval(trigtuple, tupdesc, fnumber, &isnull);
> 
> 		/*
> 		 * If it's NULL then nothing to do! DON'T FORGET call SPI_finish
> 		 * ()! DON'T FORGET return tuple! Executor inserts tuple you're
> 		 * returning! If you return NULL then nothing will be inserted!
> 		 */
> 		if (isnull)
> 		{
> 			SPI_finish();
> 			return ((newtuple == NULL) ? trigtuple : newtuple);
> 		}
> 
> 		/*
> 		 * If UPDATE then get column value from new tuple being inserted
> 		 * and compare is this the same as old one. For the moment we use
> 		 * string presentation of values...
> 		 */
> 		if (newtuple != NULL)
> 		{
> 			char	   *oldval = SPI_getvalue(trigtuple, tupdesc, fnumber);
> 			char	   *newval;
> 
> 			/* this shouldn't happen! SPI_ERROR_NOOUTFUNC ? */
> 			if (oldval == NULL)
> 				elog(ERROR, "check_foreign_key: SPI_getvalue returned %d", SPI_result);
> 			newval = SPI_getvalue(newtuple, tupdesc, fnumber);
> 			if (newval == NULL || strcmp(oldval, newval) != 0)
> 				isequal = false;
> 		}
> 
> 		if (plan->nplans <= 0)	/* Get typeId of column */
> 			argtypes[i] = SPI_gettypeid(tupdesc, fnumber);
> 	}
> 	nargs -= nkeys;
> 	args += nkeys;
> 
> 	/*
> 	 * If we have to prepare plans ...
> 	 */
> 	if (plan->nplans <= 0)
> 	{
> 		void	   *pplan;
> 		char		sql[8192];
> 		char	  **args2 = args;
> 
> 		plan->splan = (void **) malloc(nrefs * sizeof(void *));
> 
> 		for (r = 0; r < nrefs; r++)
> 		{
> 			relname = args2[0];
> 
> 			/*
> 			 * For 'R'estrict action we construct SELECT query - SELECT 1
> 			 * FROM _referencing_relation_ WHERE Fkey1 = $1 [AND Fkey2 =
> 			 * $2 [...]] - to check is tuple referenced or not.
> 			 */
> 			if (action == 'r')
> 
> 				sprintf(sql, "select 1 from %s where ", relname);
> 
> 			/*
> 			 * For 'C'ascade action we construct DELETE query - DELETE
> 			 * FROM _referencing_relation_ WHERE Fkey1 = $1 [AND Fkey2 =
> 			 * $2 [...]] - to delete all referencing tuples.
> 			 */
> 			else if (action == 'c')
> 
> 				sprintf(sql, "delete from %s where ", relname);
> 
> 			/*
> 			 * For 'S'etnull action we construct UPDATE query - UPDATE
> 			 * _referencing_relation_ SET Fkey1 null [, Fkey2 null [...]]
> 			 * WHERE Fkey1 = $1 [AND Fkey2 = $2 [...]] - to set key
> 			 * columns in all referencing tuples to NULL.
> 			 */
> 			else if (action == 's')
> 			{
> 				sprintf(sql, "update %s set ", relname);
> 				for (i = 1; i <= nkeys; i++)
> 				{
> 					sprintf(sql + strlen(sql), "%s = null%s",
> 							args2[i], (i < nkeys) ? ", " : "");
> 				}
> 				strcat(sql, " where ");
> 			}
> 
> 			/* Construct WHERE qual */
> 			for (i = 1; i <= nkeys; i++)
> 			{
> 				sprintf(sql + strlen(sql), "%s = $%d %s",
> 						args2[i], i, (i < nkeys) ? "and " : "");
> 			}
> 
> 			/* Prepare plan for query */
> 			pplan = SPI_prepare(sql, nkeys, argtypes);
> 			if (pplan == NULL)
> 				elog(ERROR, "check_foreign_key: SPI_prepare returned %d", SPI_result);
> 
> 			/*
> 			 * Remember that SPI_prepare places plan in current memory
> 			 * context - so, we have to save plan in Top memory context
> 			 * for latter use.
> 			 */
> 			pplan = SPI_saveplan(pplan);
> 			if (pplan == NULL)
> 				elog(ERROR, "check_foreign_key: SPI_saveplan returned %d", SPI_result);
> 
> 			plan->splan[r] = pplan;
> 
> 			args2 += nkeys + 1; /* to the next relation */
> 		}
> 		plan->nplans = nrefs;
> 	}
> 
> 	/*
> 	 * If UPDATE and key is not changed ...
> 	 */
> 	if (newtuple != NULL && isequal)
> 	{
> 		SPI_finish();
> 		return (newtuple);
> 	}
> 
> 	/*
> 	 * Ok, execute prepared plan(s).
> 	 */
> 	for (r = 0; r < nrefs; r++)
> 	{
> 
> 		/*
> 		 * For 'R'estrict we may to execute plan for one tuple only, for
> 		 * other actions - for all tuples.
> 		 */
> 		int			tcount = (action == 'r') ? 1 : 0;
> 
> 		relname = args[0];
> 
> 		ret = SPI_execp(plan->splan[r], kvals, NULL, tcount);
> 		/* we have no NULLs - so we pass   ^^^^  here */
> 
> 		if (ret < 0)
> 			elog(ERROR, "check_foreign_key: SPI_execp returned %d", ret);
> 
> 		/* If action is 'R'estrict ... */
> 		if (action == 'r')
> 		{
> 			/* If there is tuple returned by SELECT then ... */
> 			if (SPI_processed > 0)
> 				elog(ERROR, "%s: tuple referenced in %s",
> 					 trigger->tgname, relname);
> 		}
> #ifdef REFINT_VERBOSE
> 		else
> 			elog(NOTICE, "%s: %d tuple(s) of %s are %s",
> 				 trigger->tgname, SPI_processed, relname,
> 				 (action == 'c') ? "deleted" : "setted to null");
> #endif
> 		args += nkeys + 1;		/* to the next relation */
> 	}
> 
> 	SPI_finish();
> 
> 	return ((newtuple == NULL) ? trigtuple : newtuple);
> }
> 
> static EPlan *
> find_plan(char *ident, EPlan ** eplan, int *nplans)
> {
> 	EPlan	   *newp;
> 	int			i;
> 
> 	if (*nplans > 0)
> 	{
> 		for (i = 0; i < *nplans; i++)
> 		{
> 			if (strcmp((*eplan)[i].ident, ident) == 0)
> 				break;
> 		}
> 		if (i != *nplans)
> 			return (*eplan + i);
> 		*eplan = (EPlan *) realloc(*eplan, (i + 1) * sizeof(EPlan));
> 		newp = *eplan + i;
> 	}
> 	else
> 	{
> 		newp = *eplan = (EPlan *) malloc(sizeof(EPlan));
> 		(*nplans) = i = 0;
> 	}
> 
> 	newp->ident = (char *) malloc(strlen(ident) + 1);
> 	strcpy(newp->ident, ident);
> 	newp->nplans = 0;
> 	newp->splan = NULL;
> 	(*nplans)++;
> 
> 	return (newp);
> }


-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Sun, 14 Mar 1999 19:34:27 -0500 (EST)
Bruce Momjian <maillist@candle.pha.pa.us>
Re: [GENERAL] Foreign Keys: check_primary_function