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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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19
doc/src/sgml/func.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.144 2003/03/20 03:34:55 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.145 2003/03/20 18:58:02 momjian Exp $
PostgreSQL documentation
-->
@ -6795,6 +6795,10 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<primary>pg_get_indexdef</primary>
</indexterm>
<indexterm zone="functions-misc">
<primary>pg_get_triggerdef</primary>
</indexterm>
<indexterm zone="functions-misc">
<primary>pg_get_constraintdef</primary>
</indexterm>
@ -6808,13 +6812,13 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
extract information from the system catalogs.
<function>pg_get_viewdef</function>,
<function>pg_get_ruledef</function>,
<function>pg_get_indexdef</function>, and
<function>pg_get_indexdef()</function>,
<function>pg_get_triggerdef()</function>, and
<function>pg_get_constraintdef</function> respectively
reconstruct the creating command for a view, rule, index, or
constraint. (Note that this is a decompiled reconstruction, not
the verbatim text of the command.) At present
<function>pg_get_constraintdef</function> only works for
foreign-key constraints. <function>pg_get_userbyid</function>
the verbatim text of the command.)
<function>pg_get_userbyid</function>
extracts a user's name given a user ID number.
</para>
@ -6846,6 +6850,11 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<entry><type>text</type></entry>
<entry>get <command>CREATE INDEX</> command for index</entry>
</row>
<row>
<entry><function>pg_get_triggerdef</function>(<parameter>triggerOID</parameter>)</entry>
<entry><type>text</type></entry>
<entry>Get <command>CREATE [ CONSTRAINT ] TRIGGER</> command for trigger</entry>
</row>
<row>
<entry><literal><function>pg_get_constraintdef</function>(<parameter>constraint_oid</parameter>)</literal></entry>
<entry><type>text</type></entry>

185
src/backend/utils/adt/ruleutils.c
View File

@ -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

4
src/include/catalog/pg_proc.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_proc.h,v 1.288 2003/03/20 03:34:56 momjian Exp $
* $Id: pg_proc.h,v 1.289 2003/03/20 18:58:02 momjian Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@ -2194,6 +2194,8 @@ DATA(insert OID = 1642 ( pg_get_userbyid PGNSP PGUID 12 f f t f s 1 19 "23"
DESCR("user name by UID (with fallback)");
DATA(insert OID = 1643 ( pg_get_indexdef PGNSP PGUID 12 f f t f s 1 25 "26" pg_get_indexdef - _null_ ));
DESCR("index description");
DATA(insert OID = 1662 ( pg_get_triggerdef PGNSP PGUID 12 f f t f s 1 25 "26" pg_get_triggerdef - _null_ ));
DESCR("trigger description");
DATA(insert OID = 1387 ( pg_get_constraintdef PGNSP PGUID 12 f f t f s 1 25 "26" pg_get_constraintdef - _null_ ));
DESCR("constraint description");
DATA(insert OID = 1716 ( pg_get_expr PGNSP PGUID 12 f f t f s 2 25 "25 26" pg_get_expr - _null_ ));

3
src/include/utils/builtins.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: builtins.h,v 1.208 2003/02/13 05:24:04 momjian Exp $
* $Id: builtins.h,v 1.209 2003/03/20 18:58:02 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -399,6 +399,7 @@ extern Datum pg_get_ruledef(PG_FUNCTION_ARGS);
extern Datum pg_get_viewdef(PG_FUNCTION_ARGS);
extern Datum pg_get_viewdef_name(PG_FUNCTION_ARGS);
extern Datum pg_get_indexdef(PG_FUNCTION_ARGS);
extern Datum pg_get_triggerdef(PG_FUNCTION_ARGS);
extern Datum pg_get_constraintdef(PG_FUNCTION_ARGS);
extern Datum pg_get_userbyid(PG_FUNCTION_ARGS);
extern Datum pg_get_expr(PG_FUNCTION_ARGS);