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This patch creates a function named pg_get_triggerdef that takes the oid of

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a trigger as its parameter.  It is basically copied from the pg_dump
code.

Christopher Kings-Lynne
This commit is contained in:
Bruce Momjian
2003-03-20 18:58:02 +00:00
parent 8819213534
commit 3be6367b9f
4 changed files with 203 additions and 8 deletions
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185
src/backend/utils/adt/ruleutils.c
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@ -3,7 +3,7 @@
* back to source text
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.136 2003/02/16 02:30:39 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.137 2003/03/20 18:58:02 momjian Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -49,6 +49,7 @@
#include "catalog/pg_cast.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_index.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_shadow.h"
@ -369,6 +370,188 @@ pg_do_getviewdef(Oid viewoid)
return ruledef;
}
/* ----------
* get_triggerdef - Get the definition of a trigger
* ----------
*/
Datum
pg_get_triggerdef(PG_FUNCTION_ARGS)
{
Oid trigid = PG_GETARG_OID(0);
text *trigdef;
HeapTuple ht_trig;
HeapTuple ht_proc;
Form_pg_trigger trigrec;
int len;
StringInfoData buf;
Relation tgrel;
ScanKeyData skey[1];
SysScanDesc tgscan;
int findx = 0;
const char *tgargs;
const char *p;
char *tgfname;
char *tgname;
/*
* Fetch the pg_trigger tuple by the Oid of the trigger
*/
tgrel = heap_openr(TriggerRelationName, AccessShareLock);
/*
* Find the trigger
*/
ScanKeyEntryInitialize(&skey[0], 0x0,
ObjectIdAttributeNumber, F_OIDEQ,
ObjectIdGetDatum(trigid));
tgscan = systable_beginscan(tgrel, TriggerOidIndex, true,
SnapshotNow, 1, skey);
ht_trig = systable_getnext(tgscan);
if (!HeapTupleIsValid(ht_trig))
elog(ERROR, "pg_get_triggerdef: there is no trigger with oid %u",
trigid);
trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig);
systable_endscan(tgscan);
/*
* Fetch the pg_proc tuple of the trigger's function
*/
ht_proc = SearchSysCache(PROCOID,
ObjectIdGetDatum(trigrec->tgfoid),
0, 0, 0);
if (!HeapTupleIsValid(ht_proc))
elog(ERROR, "syscache lookup for function %u failed", trigrec->tgfoid);
tgfname = NameStr(((Form_pg_proc) GETSTRUCT(ht_proc))->proname);
/*
* Start the trigger definition. Note that the trigger's name should
* never be schema-qualified, but the trigger rel's name may be.
*/
initStringInfo(&buf);
tgname = NameStr(trigrec->tgname);
appendStringInfo(&buf, "CREATE %sTRIGGER %s ",
trigrec->tgisconstraint ? "CONSTRAINT " : "",
quote_identifier(tgname));
if (TRIGGER_FOR_BEFORE(trigrec->tgtype))
appendStringInfo(&buf, "BEFORE");
else
appendStringInfo(&buf, "AFTER");
if (TRIGGER_FOR_INSERT(trigrec->tgtype))
{
appendStringInfo(&buf, " INSERT");
findx++;
}
if (TRIGGER_FOR_DELETE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR DELETE");
else
appendStringInfo(&buf, " DELETE");
findx++;
}
if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR UPDATE");
else
appendStringInfo(&buf, " UPDATE");
}
appendStringInfo(&buf, " ON %s ",
generate_relation_name(trigrec->tgrelid));
if (trigrec->tgisconstraint)
{
if (trigrec->tgconstrrelid != 0)
{
appendStringInfo(&buf, "FROM %s ",
generate_relation_name(trigrec->tgconstrrelid));
}
if (!trigrec->tgdeferrable)
appendStringInfo(&buf, "NOT ");
appendStringInfo(&buf, "DEFERRABLE INITIALLY ");
if (trigrec->tginitdeferred)
appendStringInfo(&buf, "DEFERRED ");
else
appendStringInfo(&buf, "IMMEDIATE ");
}
if (TRIGGER_FOR_ROW(trigrec->tgtype))
appendStringInfo(&buf, "FOR EACH ROW ");
else
appendStringInfo(&buf, "FOR EACH STATEMENT ");
appendStringInfo(&buf, "EXECUTE PROCEDURE %s(",
quote_identifier(tgfname));
/* Get args string */
tgargs = DatumGetCString(DirectFunctionCall1(byteaout,
PointerGetDatum(&trigrec->tgargs)));
/* If it's NULL, fail */
if (tgargs == NULL)
elog(ERROR, "pg_get_triggerdef: tgargs is NULL");
for (findx = 0; findx < trigrec->tgnargs; findx++)
{
const char *s;
for (p = tgargs;;)
{
p = strchr(p, '\\');
if (p == NULL)
{
elog(ERROR, "pg_get_triggerdef: bad argument string for trigger");
}
p++;
if (*p == '\\')
{
p++;
continue;
}
if (p[0] == '0' && p[1] == '0' && p[2] == '0')
break;
}
p--;
appendStringInfoChar(&buf, '\'');
for (s = tgargs; s < p;)
{
/* If character is an apostrophe, escape it */
if (*s == '\'')
appendStringInfoChar(&buf, '\\');
appendStringInfoChar(&buf, *s++);
}
appendStringInfoChar(&buf, '\'');
appendStringInfo(&buf, (findx < trigrec->tgnargs - 1) ? ", " : "");
tgargs = p + 4;
}
/* Deliberately omit semi-colon */
appendStringInfo(&buf, ")");
/*
* Create the result as a TEXT datum, and free working data
*/
len = buf.len + VARHDRSZ;
trigdef = (text *) palloc(len);
VARATT_SIZEP(trigdef) = len;
memcpy(VARDATA(trigdef), buf.data, buf.len);
pfree(buf.data);
ReleaseSysCache(ht_trig);
ReleaseSysCache(ht_proc);
heap_close(tgrel, AccessShareLock);
PG_RETURN_TEXT_P(trigdef);
}
/* ----------
* get_indexdef - Get the definition of an index