Another go-round with FigureColname, to produce less surprising results

for nested typecasts.  It now produces a column header of 'timestamptz'
for 'SELECT CURRENT_TIMESTAMP', rather than 'text' as it was doing for
awhile there.

diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index c40792072b13b7f810ad8448d86ad1b5658df183..801dde811c606c63f966d8e143e528e9ec121001 100644 (file)
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.73 2001/09/28 08:09:09 thomas Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.74 2001/10/08 21:48:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,6 +27,7 @@
 
 static List *ExpandAllTables(ParseState *pstate);
 static char *FigureColname(Node *node);
+static int FigureColnameInternal(Node *node, char **name);
 
 
 /*
@@ -460,15 +461,28 @@ ExpandAllTables(ParseState *pstate)
 static char *
 FigureColname(Node *node)
 {
+   char   *name = NULL;
+
+   FigureColnameInternal(node, &name);
+   if (name != NULL)
+       return name;
+   /* default result if we can't guess anything */
+   return "?column?";
+}
+
+static int
+FigureColnameInternal(Node *node, char **name)
+{
+   int     strength = 0;
+
    if (node == NULL)
-       return "?column?";
+       return strength;
 
    switch (nodeTag(node))
    {
        case T_Ident:
-           return ((Ident *) node)->name;
-       case T_A_Const:
-           return (FigureColname((Node *)((A_Const *) node)->typename));
+           *name = ((Ident *) node)->name;
+           return 2;
        case T_Attr:
            {
                List       *attrs = ((Attr *) node)->attrs;
@@ -477,36 +491,45 @@ FigureColname(Node *node)
                {
                    while (lnext(attrs) != NIL)
                        attrs = lnext(attrs);
-                   return strVal(lfirst(attrs));
+                   *name = strVal(lfirst(attrs));
+                   return 2;
                }
            }
            break;
        case T_FuncCall:
-           return ((FuncCall *) node)->funcname;
+           *name = ((FuncCall *) node)->funcname;
+           return 2;
+       case T_A_Const:
+           if (((A_Const *) node)->typename != NULL)
+           {
+               *name = ((A_Const *) node)->typename->name;
+               return 1;
+           }
+           break;
        case T_TypeCast: 
+           strength = FigureColnameInternal(((TypeCast *) node)->arg,
+                                            name);
+           if (strength <= 1)
            {
-               char       *name;
-
-               name = FigureColname(((TypeCast *) node)->arg);
-               if (strcmp(name, "?column?") == 0)
-                 name = FigureColname((Node *)((TypeCast *) node)->typename);
-               return name;
+               if (((TypeCast *) node)->typename != NULL)
+               {
+                   *name = ((TypeCast *) node)->typename->name;
+                   return 1;
+               }
            }
            break;
        case T_CaseExpr:
+           strength = FigureColnameInternal(((CaseExpr *) node)->defresult,
+                                            name);
+           if (strength <= 1)
            {
-               char       *name;
-
-               name = FigureColname(((CaseExpr *) node)->defresult);
-               if (strcmp(name, "?column?") == 0)
-                   name = "case";
-               return name;
+               *name = "case";
+               return 1;
            }
            break;
-       case T_TypeName:
-           return ((TypeName *) node)->name;
        default:
            break;
    }
-   return "?column?";
+
+   return strength;
 }