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

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

Christopher Kings-Lynne

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 256b0fa3fae42e52e5d5abeab52c250743732b07..27966276d0e14bc4d52542fdc7b5ffadb4f17764 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -6795,6 +6795,10 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
     pg_get_indexdef
    
 
+   
+    pg_get_triggerdef
+   
+
    
     pg_get_constraintdef
    
@@ -6808,13 +6812,13 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
    extract information from the system catalogs.
    pg_get_viewdef,
    pg_get_ruledef,
-   pg_get_indexdef, and
+   pg_get_indexdef(),
+   pg_get_triggerdef(), and
    pg_get_constraintdef 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
-   pg_get_constraintdef only works for
-   foreign-key constraints.  pg_get_userbyid
+   the verbatim text of the command.)
+   pg_get_userbyid
    extracts a user's name given a user ID number.
   
 
@@ -6846,6 +6850,11 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
        text
        get CREATE INDEX command for index
       
+      
+       pg_get_triggerdef(triggerOID)
+       text
+       Get CREATE [ CONSTRAINT ] TRIGGER command for trigger
+      
       
        pg_get_constraintdef(constraint_oid)
        text

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index dfed27f89dab7a8ab2d061d02ce35924258237a3..9b34544a3872313561739f6295ea6af9e5b08394 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -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

diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 0938ba0b4768e9ac9faf84ff8d816e1747d0f839..835d6f2b5bb8d43ba9b12c7fe635798b46da9739 100644 (file)
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -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_ ));

diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index e956f54fef6527c591c4f6cc5f78aa1cfb059539..3a2b20eacbd3c6225f0ceaf4d91827ba2cbab208 100644 (file)
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -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);