<!--
-$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
-->
<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>
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>
<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>
* 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.
*
#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"
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
projects / postgresql / commitdiff