Prepare the EXTRACT() clause for supporting TIMEZONE_HOUR

 and TIMEZONE_MINUTE but don't introduce until v6.4.
Fix SET TIMEZONE LOCAL to pass null pointer
 rather than older "default" string.
Fix handling of NULL pointer returns from FOREIGN KEY clauses
 which are currently ignored.
Allow START as a table/column name.

src/backend/parser/gram.y

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.8 1998/03/30 16:36:35 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.9 1998/04/08 06:38:57 thomas Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -215,6 +215,7 @@ Oid	param_type(int t); /* used in parse_expr.c */
 
 %type <typnam>	Typename, opt_type, Array, Generic, Character, Datetime, Numeric
 %type <str>		generic, numeric, character, datetime
+%type <str>		extract_arg
 %type <str>		opt_charset, opt_collate
 %type <str>		opt_float, opt_numeric, opt_decimal
 %type <boolean>	opt_varying, opt_timezone
@@ -540,7 +541,7 @@ var_value:  Sconst			{ $$ = $1; }
 
 zone_value:  Sconst			{ $$ = $1; }
 		| DEFAULT			{ $$ = NULL; }
-		| LOCAL				{ $$ = "default"; }
+		| LOCAL				{ $$ = NULL; }
 		;
 
 VariableShowStmt:  SHOW ColId
@@ -701,8 +702,19 @@ CreateStmt:  CREATE TABLE relation_name '(' OptTableElementList ')'
 		;
 
 OptTableElementList:  OptTableElementList ',' OptTableElement
-												{ $$ = lappend($1, $3); }
-			| OptTableElement					{ $$ = lcons($1, NIL); }
+				{
+					if ($3 != NULL)
+						$$ = lappend($1, $3);
+					else
+						$$ = $1;
+				}
+			| OptTableElement
+				{
+					if ($1 != NULL)
+						$$ = lcons($1, NIL);
+					else
+						$$ = NULL;
+				}
 			| /*EMPTY*/							{ $$ = NULL; }
 		;
 
@@ -734,7 +746,7 @@ ColConstraint:
 		CONSTRAINT name ColConstraintElem
 				{
 						Constraint *n = (Constraint *)$3;
-						n->name = fmtId($2);
+						if (n != NULL) n->name = fmtId($2);
 						$$ = $3;
 				}
 		| ColConstraintElem
@@ -893,7 +905,7 @@ default_expr:  AexprConst
 TableConstraint:  CONSTRAINT name ConstraintElem
 				{
 						Constraint *n = (Constraint *)$3;
-						n->name = fmtId($2);
+						if (n != NULL) n->name = fmtId($2);
 						$$ = $3;
 				}
 		| ConstraintElem
@@ -927,7 +939,10 @@ ConstraintElem:  CHECK '(' constraint_expr ')'
 					$$ = (Node *)n;
 				}
 		| FOREIGN KEY '(' columnList ')' REFERENCES ColId opt_column_list key_match key_actions
-				{	elog(NOTICE,"CREATE TABLE/FOREIGN KEY clause ignored; not yet implemented"); }
+				{
+					elog(NOTICE,"CREATE TABLE/FOREIGN KEY clause ignored; not yet implemented");
+					$$ = NULL;
+				}
 		;
 
 constraint_list:  constraint_list ',' constraint_expr
@@ -4164,7 +4179,7 @@ expr_list:  a_expr_or_null
 				{ $$ = lappend($1, $3); }
 		;
 
-extract_list:  datetime FROM a_expr
+extract_list:  extract_arg FROM a_expr
 				{
 					A_Const *n = makeNode(A_Const);
 					n->val.type = T_String;
@@ -4175,6 +4190,14 @@ extract_list:  datetime FROM a_expr
 				{	$$ = NIL; }
 		;
 
+/* Add in TIMEZONE_HOUR and TIMEZONE_MINUTE for SQL92 compliance
+ *  for next release. Just set up extract_arg for now...
+ * - thomas 1998-04-08
+ */
+extract_arg:  datetime
+				{	$$ = $1; }
+		;
+
 position_list:  position_expr IN position_expr
 				{	$$ = makeList($3, $1, -1); }
 		| /* EMPTY */
@@ -4660,6 +4683,7 @@ ColId:  IDENT							{ $$ = $1; }
 		| PRIVILEGES					{ $$ = "privileges"; }
 		| RECIPE						{ $$ = "recipe"; }
 		| ROW							{ $$ = "row"; }
+		| START							{ $$ = "start"; }
 		| STATEMENT						{ $$ = "statement"; }
 		| TIME							{ $$ = "time"; }
 		| TRIGGER						{ $$ = "trigger"; }