Added SET DEFAULT action for ON DELETE/UPDATE
authorJan Wieck
Tue, 7 Dec 1999 00:11:35 +0000 (00:11 +0000)
committerJan Wieck
Tue, 7 Dec 1999 00:11:35 +0000 (00:11 +0000)
Jan

src/backend/utils/adt/ri_triggers.c

index 94d434f9665903ec2bc38a8efdb04940d3ca6c3f..c1749a332de4c52b6ea872c77774ebc799772325 100644 (file)
@@ -6,7 +6,7 @@
  *
  * 1999 Jan Wieck
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.6 1999/12/06 19:52:36 wieck Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.7 1999/12/07 00:11:35 wieck Exp $
  *
  * ----------
  */
@@ -31,6 +31,7 @@
 #include "catalog/catname.h"
 #include "commands/trigger.h"
 #include "executor/spi.h"
+#include "executor/spi_priv.h"
 #include "utils/builtins.h"
 #include "utils/mcxt.h"
 #include "utils/syscache.h"
@@ -334,17 +335,15 @@ RI_FKey_check (FmgrInfo *proinfo)
            heap_close(pk_rel, NoLock);
 
            /* ----------
-            * If we're called on UPDATE, check if there was a change
-            * in the foreign key at all.
+            * Note:
+            * We cannot avoid the check on UPDATE, even if old and new
+            * key are the same. Otherwise, someone could DELETE the PK
+            * that consists of the DEFAULT values, and if there are any
+            * references, a ON DELETE SET DEFAULT action would update
+            * the references to exactly these values but we wouldn't see
+            * that weired case (this is the only place to see it).
             * ----------
             */
-           if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
-           {
-               if (ri_KeysEqual(fk_rel, old_row, new_row, &qkey,
-                                                       RI_KEYPAIR_FK_IDX))
-                   return NULL;
-           }
-
            if (SPI_connect() != SPI_OK_CONNECT)
                elog(NOTICE, "SPI_connect() failed in RI_FKey_check()");
 
@@ -1454,7 +1453,7 @@ RI_FKey_setnull_del (FmgrInfo *proinfo)
                 * Prepare, save and remember the new plan.
                 * ----------
                 */
-               qplan = SPI_prepare(querystr, qkey.nkeypairs * 2, queryoids);
+               qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
                qplan = SPI_saveplan(qplan);
                ri_HashPreparedPlan(&qkey, qplan);
            }
@@ -1673,7 +1672,7 @@ RI_FKey_setnull_upd (FmgrInfo *proinfo)
                 * Prepare, save and remember the new plan.
                 * ----------
                 */
-               qplan = SPI_prepare(querystr, qkey.nkeypairs * 2, queryoids);
+               qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
                qplan = SPI_saveplan(qplan);
                ri_HashPreparedPlan(&qkey, qplan);
            }
@@ -1735,12 +1734,239 @@ RI_FKey_setnull_upd (FmgrInfo *proinfo)
 HeapTuple
 RI_FKey_setdefault_del (FmgrInfo *proinfo)
 {
-   TriggerData         *trigdata;
+   TriggerData        *trigdata;
+   int                 tgnargs;
+   char              **tgargs;
+   Relation            fk_rel;
+   Relation            pk_rel;
+   HeapTuple           old_row;
+   RI_QueryKey         qkey;
+   void               *qplan;
+   Datum               upd_values[RI_MAX_NUMKEYS];
+   char                upd_nulls[RI_MAX_NUMKEYS + 1];
+   bool                isnull;
+   int                 i;
 
    trigdata = CurrentTriggerData;
    CurrentTriggerData  = NULL;
 
-   elog(ERROR, "RI_FKey_setdefault_del() called\n");
+   /* ----------
+    * Check that this is a valid trigger call on the right time and event.
+    * ----------
+    */
+   if (trigdata == NULL)
+       elog(ERROR, "RI_FKey_setdefault_del() not fired by trigger manager");
+   if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) || 
+               !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
+       elog(ERROR, "RI_FKey_setdefault_del() must be fired AFTER ROW");
+   if (!TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
+       elog(ERROR, "RI_FKey_setdefault_del() must be fired for DELETE");
+
+   /* ----------
+    * Check for the correct # of call arguments 
+    * ----------
+    */
+   tgnargs = trigdata->tg_trigger->tgnargs;
+   tgargs  = trigdata->tg_trigger->tgargs;
+   if (tgnargs < 4 || (tgnargs % 2) != 0)
+       elog(ERROR, "wrong # of arguments in call to RI_FKey_setdefault_del()");
+   if (tgnargs > RI_MAX_ARGUMENTS)
+       elog(ERROR, "too many keys (%d max) in call to RI_FKey_setdefault_del()",
+                       RI_MAX_NUMKEYS);
+
+   /* ----------
+    * Nothing to do if no column names to compare given
+    * ----------
+    */
+   if (tgnargs == 4)
+       return NULL;
+
+   /* ----------
+    * Get the relation descriptors of the FK and PK tables and
+    * the old tuple.
+    * ----------
+    */
+   fk_rel  = heap_openr(tgargs[RI_FK_RELNAME_ARGNO], NoLock);
+   pk_rel  = trigdata->tg_relation;
+   old_row = trigdata->tg_trigtuple;
+
+   switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
+   {
+       /* ----------
+        * SQL3 11.9 
+        *  Gereral rules 6) a) iii):
+        *      MATCH  or MATCH FULL
+        *          ... ON DELETE SET DEFAULT
+        * ----------
+        */
+       case RI_MATCH_TYPE_UNSPECIFIED:
+       case RI_MATCH_TYPE_FULL:
+           ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
+                                   RI_PLAN_SETNULL_DEL_DOUPDATE,
+                                   fk_rel, pk_rel,
+                                   tgnargs, tgargs);
+
+           switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
+           {
+               case RI_KEYS_ALL_NULL:
+               case RI_KEYS_SOME_NULL:
+                   /* ----------
+                    * No update - MATCH FULL means there cannot be any
+                    * reference to old key if it contains NULL
+                    * ----------
+                    */
+                   heap_close(fk_rel, NoLock);
+                   return NULL;
+                   
+               case RI_KEYS_NONE_NULL:
+                   /* ----------
+                    * Have a full qualified key - continue below
+                    * ----------
+                    */
+                   break;
+           }
+           heap_close(fk_rel, NoLock);
+
+           if (SPI_connect() != SPI_OK_CONNECT)
+               elog(NOTICE, "SPI_connect() failed in RI_FKey_setdefault_del()");
+
+           /* ----------
+            * Prepare a plan for the set defalt delete operation.
+            * Unfortunately we need to do it on every invocation
+            * because the default value could potentially change
+            * between calls.
+            * ----------
+            */
+           {
+               char        buf[256];
+               char        querystr[8192];
+               char        qualstr[8192];
+               char        *querysep;
+               char        *qualsep;
+               Oid         queryoids[RI_MAX_NUMKEYS];
+               Plan        *spi_plan;
+               AttrDefault *defval;
+               TargetEntry *spi_qptle;
+               int         i, j;
+
+               /* ----------
+                * The query string built is
+                *    UPDATE  SET fkatt1 = NULL [, ...]
+                *          WHERE fkatt1 = $1 [AND ...]
+                * The type id's for the $ parameters are those of the
+                * corresponding PK attributes. Thus, SPI_prepare could
+                * eventually fail if the parser cannot identify some way
+                * how to compare these two types by '='.
+                * ----------
+                */
+               sprintf(querystr, "UPDATE \"%s\" SET", 
+                                   tgargs[RI_FK_RELNAME_ARGNO]);
+               qualstr[0] = '\0';
+               querysep = "";
+               qualsep = "WHERE";
+               for (i = 0; i < qkey.nkeypairs; i++)
+               {
+                   sprintf(buf, "%s \"%s\" = NULL", querysep, 
+                                       tgargs[4 + i * 2]);
+                   strcat(querystr, buf);
+                   sprintf(buf, " %s \"%s\" = $%d", qualsep,
+                                       tgargs[4 + i * 2], i + 1);
+                   strcat(qualstr, buf);
+                   querysep = ",";
+                   qualsep = "AND";
+                   queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
+                                   qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
+               }
+               strcat(querystr, qualstr);
+
+               /* ----------
+                * Prepare the plan
+                * ----------
+                */
+               qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
+
+               /* ----------
+                * Now replace the CONST NULL targetlist expressions
+                * in the generated plan by (any) default values found
+                * in the tuple constructor.
+                * ----------
+                */
+               spi_plan = (Plan *)lfirst(((_SPI_plan *)qplan)->ptlist);
+               if (fk_rel->rd_att->constr != NULL)
+                   defval = fk_rel->rd_att->constr->defval;
+               else
+                   defval = NULL;
+               for (i = 0; i < qkey.nkeypairs && defval != NULL; i++)
+               {
+                   /* ----------
+                    * For each key attribute lookup the tuple constructor
+                    * for a corresponding default value
+                    * ----------
+                    */
+                   for (j = 0; j < fk_rel->rd_att->constr->num_defval; j++)
+                   {
+                       if (defval[j].adnum == 
+                                           qkey.keypair[i][RI_KEYPAIR_FK_IDX])
+                       {
+                           /* ----------
+                            * That's the one - push the expression
+                            * from defval.adbin into the plan's targetlist
+                            * ----------
+                            */
+                           spi_qptle = (TargetEntry *)
+                                       nth(i, spi_plan->targetlist);
+                           spi_qptle->expr = stringToNode(defval[j].adbin);
+
+                           break;
+                       }
+                   }
+               }
+           }
+
+           /* ----------
+            * We have a plan now. Build up the arguments for SPI_execp()
+            * from the key values in the deleted PK tuple.
+            * ----------
+            */
+           for (i = 0; i < qkey.nkeypairs; i++)
+           {
+               upd_values[i] = SPI_getbinval(old_row,
+                                   pk_rel->rd_att,
+                                   qkey.keypair[i][RI_KEYPAIR_PK_IDX],
+                                   &isnull);
+               if (isnull) 
+                   upd_nulls[i] = 'n';
+               else
+                   upd_nulls[i] = ' ';
+           }
+           upd_nulls[i] = '\0';
+
+           /* ----------
+            * Now update the existing references
+            * ----------
+            */
+           if (SPI_execp(qplan, upd_values, upd_nulls, 0) != SPI_OK_UPDATE)
+               elog(ERROR, "SPI_execp() failed in RI_FKey_setdefault_del()");
+           
+           if (SPI_finish() != SPI_OK_FINISH)
+               elog(NOTICE, "SPI_finish() failed in RI_FKey_setdefault_del()");
+
+           return NULL;
+
+       /* ----------
+        * Handle MATCH PARTIAL set null delete.
+        * ----------
+        */
+       case RI_MATCH_TYPE_PARTIAL:
+           elog(ERROR, "MATCH PARTIAL not yet supported");
+           return NULL;
+   }
+
+   /* ----------
+    * Never reached
+    * ----------
+    */
+   elog(ERROR, "internal error #8 in ri_triggers.c");
    return NULL;
 }
 
@@ -1754,12 +1980,249 @@ RI_FKey_setdefault_del (FmgrInfo *proinfo)
 HeapTuple
 RI_FKey_setdefault_upd (FmgrInfo *proinfo)
 {
-   TriggerData         *trigdata;
+   TriggerData        *trigdata;
+   int                 tgnargs;
+   char              **tgargs;
+   Relation            fk_rel;
+   Relation            pk_rel;
+   HeapTuple           new_row;
+   HeapTuple           old_row;
+   RI_QueryKey         qkey;
+   void               *qplan;
+   Datum               upd_values[RI_MAX_NUMKEYS];
+   char                upd_nulls[RI_MAX_NUMKEYS + 1];
+   bool                isnull;
+   int                 i;
 
    trigdata = CurrentTriggerData;
    CurrentTriggerData  = NULL;
 
-   elog(ERROR, "RI_FKey_setdefault_upd() called\n");
+   /* ----------
+    * Check that this is a valid trigger call on the right time and event.
+    * ----------
+    */
+   if (trigdata == NULL)
+       elog(ERROR, "RI_FKey_setdefault_upd() not fired by trigger manager");
+   if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) || 
+               !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
+       elog(ERROR, "RI_FKey_setdefault_upd() must be fired AFTER ROW");
+   if (!TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
+       elog(ERROR, "RI_FKey_setdefault_upd() must be fired for UPDATE");
+
+   /* ----------
+    * Check for the correct # of call arguments 
+    * ----------
+    */
+   tgnargs = trigdata->tg_trigger->tgnargs;
+   tgargs  = trigdata->tg_trigger->tgargs;
+   if (tgnargs < 4 || (tgnargs % 2) != 0)
+       elog(ERROR, "wrong # of arguments in call to RI_FKey_setdefault_upd()");
+   if (tgnargs > RI_MAX_ARGUMENTS)
+       elog(ERROR, "too many keys (%d max) in call to RI_FKey_setdefault_upd()",
+                       RI_MAX_NUMKEYS);
+
+   /* ----------
+    * Nothing to do if no column names to compare given
+    * ----------
+    */
+   if (tgnargs == 4)
+       return NULL;
+
+   /* ----------
+    * Get the relation descriptors of the FK and PK tables and
+    * the old tuple.
+    * ----------
+    */
+   fk_rel  = heap_openr(tgargs[RI_FK_RELNAME_ARGNO], NoLock);
+   pk_rel  = trigdata->tg_relation;
+   new_row = trigdata->tg_newtuple;
+   old_row = trigdata->tg_trigtuple;
+
+   switch (ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]))
+   {
+       /* ----------
+        * SQL3 11.9 
+        *  Gereral rules 7) a) iii):
+        *      MATCH  or MATCH FULL
+        *          ... ON UPDATE SET DEFAULT
+        * ----------
+        */
+       case RI_MATCH_TYPE_UNSPECIFIED:
+       case RI_MATCH_TYPE_FULL:
+           ri_BuildQueryKeyFull(&qkey, trigdata->tg_trigger->tgoid,
+                                   RI_PLAN_SETNULL_DEL_DOUPDATE,
+                                   fk_rel, pk_rel,
+                                   tgnargs, tgargs);
+
+           switch (ri_NullCheck(pk_rel, old_row, &qkey, RI_KEYPAIR_PK_IDX))
+           {
+               case RI_KEYS_ALL_NULL:
+               case RI_KEYS_SOME_NULL:
+                   /* ----------
+                    * No update - MATCH FULL means there cannot be any
+                    * reference to old key if it contains NULL
+                    * ----------
+                    */
+                   heap_close(fk_rel, NoLock);
+                   return NULL;
+                   
+               case RI_KEYS_NONE_NULL:
+                   /* ----------
+                    * Have a full qualified key - continue below
+                    * ----------
+                    */
+                   break;
+           }
+           heap_close(fk_rel, NoLock);
+
+           /* ----------
+            * No need to do anything if old and new keys are equal
+            * ----------
+            */
+           if (ri_KeysEqual(pk_rel, old_row, new_row, &qkey,
+                                                   RI_KEYPAIR_PK_IDX))
+               return NULL;
+
+           if (SPI_connect() != SPI_OK_CONNECT)
+               elog(NOTICE, "SPI_connect() failed in RI_FKey_setdefault_upd()");
+
+           /* ----------
+            * Prepare a plan for the set defalt delete operation.
+            * Unfortunately we need to do it on every invocation
+            * because the default value could potentially change
+            * between calls.
+            * ----------
+            */
+           {
+               char        buf[256];
+               char        querystr[8192];
+               char        qualstr[8192];
+               char        *querysep;
+               char        *qualsep;
+               Oid         queryoids[RI_MAX_NUMKEYS];
+               Plan        *spi_plan;
+               AttrDefault *defval;
+               TargetEntry *spi_qptle;
+               int         i, j;
+
+               /* ----------
+                * The query string built is
+                *    UPDATE  SET fkatt1 = NULL [, ...]
+                *          WHERE fkatt1 = $1 [AND ...]
+                * The type id's for the $ parameters are those of the
+                * corresponding PK attributes. Thus, SPI_prepare could
+                * eventually fail if the parser cannot identify some way
+                * how to compare these two types by '='.
+                * ----------
+                */
+               sprintf(querystr, "UPDATE \"%s\" SET", 
+                                   tgargs[RI_FK_RELNAME_ARGNO]);
+               qualstr[0] = '\0';
+               querysep = "";
+               qualsep = "WHERE";
+               for (i = 0; i < qkey.nkeypairs; i++)
+               {
+                   sprintf(buf, "%s \"%s\" = NULL", querysep, 
+                                       tgargs[4 + i * 2]);
+                   strcat(querystr, buf);
+                   sprintf(buf, " %s \"%s\" = $%d", qualsep,
+                                       tgargs[4 + i * 2], i + 1);
+                   strcat(qualstr, buf);
+                   querysep = ",";
+                   qualsep = "AND";
+                   queryoids[i] = SPI_gettypeid(pk_rel->rd_att,
+                                   qkey.keypair[i][RI_KEYPAIR_PK_IDX]);
+               }
+               strcat(querystr, qualstr);
+
+               /* ----------
+                * Prepare the plan
+                * ----------
+                */
+               qplan = SPI_prepare(querystr, qkey.nkeypairs, queryoids);
+
+               /* ----------
+                * Now replace the CONST NULL targetlist expressions
+                * in the generated plan by (any) default values found
+                * in the tuple constructor.
+                * ----------
+                */
+               spi_plan = (Plan *)lfirst(((_SPI_plan *)qplan)->ptlist);
+               if (fk_rel->rd_att->constr != NULL)
+                   defval = fk_rel->rd_att->constr->defval;
+               else
+                   defval = NULL;
+               for (i = 0; i < qkey.nkeypairs && defval != NULL; i++)
+               {
+                   /* ----------
+                    * For each key attribute lookup the tuple constructor
+                    * for a corresponding default value
+                    * ----------
+                    */
+                   for (j = 0; j < fk_rel->rd_att->constr->num_defval; j++)
+                   {
+                       if (defval[j].adnum == 
+                                           qkey.keypair[i][RI_KEYPAIR_FK_IDX])
+                       {
+                           /* ----------
+                            * That's the one - push the expression
+                            * from defval.adbin into the plan's targetlist
+                            * ----------
+                            */
+                           spi_qptle = (TargetEntry *)
+                                       nth(i, spi_plan->targetlist);
+                           spi_qptle->expr = stringToNode(defval[j].adbin);
+
+                           break;
+                       }
+                   }
+               }
+           }
+
+           /* ----------
+            * We have a plan now. Build up the arguments for SPI_execp()
+            * from the key values in the deleted PK tuple.
+            * ----------
+            */
+           for (i = 0; i < qkey.nkeypairs; i++)
+           {
+               upd_values[i] = SPI_getbinval(old_row,
+                                   pk_rel->rd_att,
+                                   qkey.keypair[i][RI_KEYPAIR_PK_IDX],
+                                   &isnull);
+               if (isnull) 
+                   upd_nulls[i] = 'n';
+               else
+                   upd_nulls[i] = ' ';
+           }
+           upd_nulls[i] = '\0';
+
+           /* ----------
+            * Now update the existing references
+            * ----------
+            */
+           if (SPI_execp(qplan, upd_values, upd_nulls, 0) != SPI_OK_UPDATE)
+               elog(ERROR, "SPI_execp() failed in RI_FKey_setdefault_upd()");
+           
+           if (SPI_finish() != SPI_OK_FINISH)
+               elog(NOTICE, "SPI_finish() failed in RI_FKey_setdefault_upd()");
+
+           return NULL;
+
+       /* ----------
+        * Handle MATCH PARTIAL set null delete.
+        * ----------
+        */
+       case RI_MATCH_TYPE_PARTIAL:
+           elog(ERROR, "MATCH PARTIAL not yet supported");
+           return NULL;
+   }
+
+   /* ----------
+    * Never reached
+    * ----------
+    */
+   elog(ERROR, "internal error #9 in ri_triggers.c");
    return NULL;
 }