Make rule lister use aliases from FROM clause when a table column has

been given an alias.  Otherwise, results are incorrect.

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 26ebe21..45282fd 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 1.61 2000/09/12 21:07:05 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.62 2000/09/18 20:14:23 tgl Exp $
  *
  *       This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -109,7 +109,8 @@ static void get_from_clause_item(Node *jtnode, Query *query,
 static bool tleIsArrayAssign(TargetEntry *tle);
 static char *quote_identifier(char *ident);
 static char *get_relation_name(Oid relid);
-static char *get_attribute_name(Oid relid, int2 attnum);
+static char *get_relid_attribute_name(Oid relid, AttrNumber attnum);
+static char *get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum);
 
 #define only_marker(rte)  ((rte)->inh ? "" : "ONLY ")
 
@@ -445,7 +446,7 @@ pg_get_indexdef(PG_FUNCTION_ARGS)
                 * ----------
                 */
                appendStringInfo(&keybuf, "%s",
-                                       quote_identifier(get_attribute_name(idxrec->indrelid,
+                               quote_identifier(get_relid_attribute_name(idxrec->indrelid,
                                                                                                idxrec->indkey[keyno])));
 
                /* ----------
@@ -696,8 +697,8 @@ make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc)
                                         quote_identifier(get_relation_name(ev_class)));
        if (ev_attr > 0)
                appendStringInfo(buf, ".%s",
-                                                quote_identifier(get_attribute_name(ev_class,
-                                                                                                                        ev_attr)));
+                                                quote_identifier(get_relid_attribute_name(ev_class,
+                                                                                                                                  ev_attr)));
 
        /* If the rule has an event qualification, add it */
        if (ev_qual == NULL)
@@ -908,7 +909,7 @@ get_select_query_def(Query *query, deparse_context *context)
                        char       *attname;
 
                        rte = get_rte_for_var(var, context);
-                       attname = get_attribute_name(rte->relid, var->varattno);
+                       attname = get_rte_attribute_name(rte, var->varattno);
                        tell_as = (strcmp(attname, tle->resdom->resname) != 0);
                }
 
@@ -1164,7 +1165,7 @@ get_rule_expr(Node *node, deparse_context *context)
                                                                        quote_identifier(rte->eref->relname));
                                }
                                appendStringInfo(buf, "%s",
-                                                 quote_identifier(get_attribute_name(rte->relid,
+                                                 quote_identifier(get_rte_attribute_name(rte,
                                                                                                                var->varattno)));
                        }
                        break;
@@ -1340,7 +1341,8 @@ get_rule_expr(Node *node, deparse_context *context)
                                if (!OidIsValid(typrelid))
                                        elog(ERROR, "Argument type %s of FieldSelect is not a tuple type",
                                                 NameStr(typeStruct->typname));
-                               fieldname = get_attribute_name(typrelid, fselect->fieldnum);
+                               fieldname = get_relid_attribute_name(typrelid,
+                                                                                                        fselect->fieldnum);
                                appendStringInfo(buf, ".%s", quote_identifier(fieldname));
                        }
                        break;
@@ -2000,23 +2002,51 @@ get_relation_name(Oid relid)
 
 
 /* ----------
- * get_attribute_name                  - Get an attribute name by its
- *                                       relations Oid and its attnum
+ * get_relid_attribute_name
+ *             Get an attribute name by its relations Oid and its attnum
+ *
+ * Same as underlying syscache routine get_attname(), except that error
+ * is handled by elog() instead of returning NULL.
  * ----------
  */
 static char *
-get_attribute_name(Oid relid, int2 attnum)
+get_relid_attribute_name(Oid relid, AttrNumber attnum)
 {
-       HeapTuple       atttup;
-       Form_pg_attribute attStruct;
+       char       *attname;
 
-       atttup = SearchSysCacheTuple(ATTNUM,
-                                                                ObjectIdGetDatum(relid), (Datum) attnum,
-                                                                0, 0);
-       if (!HeapTupleIsValid(atttup))
+       attname = get_attname(relid, attnum);
+       if (attname == NULL)
                elog(ERROR, "cache lookup of attribute %d in relation %u failed",
                         attnum, relid);
+       return attname;
+}
 
-       attStruct = (Form_pg_attribute) GETSTRUCT(atttup);
-       return pstrdup(NameStr(attStruct->attname));
+/* ----------
+ * get_rte_attribute_name
+ *             Get an attribute name from a RangeTblEntry
+ *
+ * This is unlike get_relid_attribute_name() because we use aliases if
+ * available.
+ * ----------
+ */
+static char *
+get_rte_attribute_name(RangeTblEntry *rte, AttrNumber attnum)
+{
+       /*
+        * If there is an alias, use it
+        */
+       if (attnum > 0 && attnum <= length(rte->eref->attrs))
+               return strVal(nth(attnum-1, rte->eref->attrs));
+       /*
+        * Can get here for a system attribute (which never has an alias),
+        * or if alias name list is too short (which probably can't happen
+        * anymore).  Neither of these cases is valid for a subselect RTE.
+        */
+       if (rte->relid == InvalidOid)
+               elog(ERROR, "Invalid attnum %d for rangetable entry %s",
+                        attnum, rte->eref->relname);
+       /*
+        * Use the real name of the table's column
+        */
+       return get_relid_attribute_name(rte->relid, attnum);
 }