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 26ebe21c4a2c17b6bd34c81782e17a90d07c4991..45282fd94c848546af1674902f8cba6e30af3d49 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);
 }