Fixes:

scrappy · scrappy · commit 20288400f3ad · 1996-07-19T07:24:11.000Z
I have written some patches which add support for NULLs to Postgres95.
In fact support for NULLs was already present in postgres, but it had been
disabled because not completely debugged, I believe. My patches simply add
some checks here and there. To enable the new code you must add -DNULL_PATCH
to CFLAGS in Makefile.global. After recompiling you can do things like:

insert into a (x, y) values (1, NULL);
update a set x = NULL where x = 0;

You can't still use a "where x=NULL" clause, you must use ISNULL instead.
This could probably be an easy fix to do.




Submitted by: Massimo Dal Zotto &lt;dz@cs.unitn.it&gt;
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.1.1.1 1996/07/09 06:21:39 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.2 1996/07/19 07:24:06 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1313,6 +1313,11 @@ make_targetlist_expr(ParseState *pstate,
 	 elog(WARN, "make_targetlist_expr: invalid use of NULL expression");
 
      type_id = exprType(expr);
+#ifdef NULL_PATCH
+     if (!type_id) {
+	 type_len = 0;
+     } else
+#endif
      type_len = tlen(get_id_type(type_id));
 
      /* I have no idea what the following does! */
diff --git a/src/backend/parser/catalog_utils.c b/src/backend/parser/catalog_utils.c
@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/catalog_utils.c,v 1.1.1.1 1996/07/09 06:21:40 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/catalog_utils.c,v 1.2 1996/07/19 07:24:08 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -471,6 +471,11 @@ oper(char *op, int arg1, int arg2)
     CandidateList candidates;
     int ncandidates;
 
+#ifdef NULL_PATCH
+    if (!arg2) arg2=arg1;
+    if (!arg1) arg1=arg2;
+#endif
+
     if (!(tup = SearchSysCacheTuple(OPRNAME,
 				    PointerGetDatum(op),
 				    ObjectIdGetDatum(arg1),
diff --git a/src/backend/parser/parse_query.c b/src/backend/parser/parse_query.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.1.1.1 1996/07/09 06:21:40 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.2 1996/07/19 07:24:09 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -617,7 +617,11 @@ make_const(Value *value)
 
 	    /* null const */
 	    con = makeConst(0, 0, (Datum)NULL, TRUE, 0, FALSE);
+#ifdef NULL_PATCH
+	    return con;
+#else
 	    return NULL /*con*/;
+#endif
 	}
     }
 
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/parser.c,v 1.1.1.1 1996/07/09 06:21:40 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/parser.c,v 1.2 1996/07/19 07:24:11 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -302,6 +302,10 @@ parser_typecast2(Node *expr, int exprType, Type tp, int typlen)
     Assert(IsA(expr,Const));
     
     switch (exprType) {
+#ifdef NULL_PATCH
+      case 0: /* NULL */
+	break;
+#endif
     case 23: /* int4 */
 	const_string = (char *) palloc(256);
 	string_palloced = true;
@@ -352,6 +356,18 @@ parser_typecast2(Node *expr, int exprType, Type tp, int typlen)
 	elog(WARN,"unknown type%d ",exprType);
     }
     
+#ifdef NULL_PATCH
+    if (!exprType) {
+	adt = makeConst((Oid)typeid(tp),
+			(Size) 0,
+			(Datum) NULL,
+			true, 	/* isnull */
+			0 	/* was omitted */,
+			0 	/* not a set */);
+	return ((Node*) adt);
+    }
+#endif
+
     cp = instr2 (tp, const_string, typlen);
     
     

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@`
`7`	`7`	`*`
`8`	`8`	`*`
`9`	`9`	`* IDENTIFICATION`
`10`		`- * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.1.1.1 1996/07/09 06:21:39 scrappy Exp $`
	`10`	`+ * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.2 1996/07/19 07:24:06 scrappy Exp $`
`11`	`11`	`*`
`12`	`12`	`*-------------------------------------------------------------------------`
`13`	`13`	`*/`
`@@ -1313,6 +1313,11 @@ make_targetlist_expr(ParseState *pstate,`
`1313`	`1313`	`elog(WARN, "make_targetlist_expr: invalid use of NULL expression");`
`1314`	`1314`
`1315`	`1315`	`type_id = exprType(expr);`
	`1316`	`+#ifdef NULL_PATCH`
	`1317`	`+ if (!type_id) {`
	`1318`	`+ type_len = 0;`
	`1319`	`+ } else`
	`1320`	`+#endif`
`1316`	`1321`	`type_len = tlen(get_id_type(type_id));`
`1317`	`1322`
`1318`	`1323`	`/* I have no idea what the following does! */`
Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,7 @@`
`6`	`6`	`*`
`7`	`7`	`*`
`8`	`8`	`* IDENTIFICATION`
`9`		`- * $Header: /cvsroot/pgsql/src/backend/parser/Attic/catalog_utils.c,v 1.1.1.1 1996/07/09 06:21:40 scrappy Exp $`
	`9`	`+ * $Header: /cvsroot/pgsql/src/backend/parser/Attic/catalog_utils.c,v 1.2 1996/07/19 07:24:08 scrappy Exp $`
`10`	`10`	`*`
`11`	`11`	`*-------------------------------------------------------------------------`
`12`	`12`	`*/`
`@@ -471,6 +471,11 @@ oper(char *op, int arg1, int arg2)`
`471`	`471`	`CandidateList candidates;`
`472`	`472`	`int ncandidates;`
`473`	`473`
	`474`	`+#ifdef NULL_PATCH`
	`475`	`+ if (!arg2) arg2=arg1;`
	`476`	`+ if (!arg1) arg1=arg2;`
	`477`	`+#endif`
	`478`	`+`
`474`	`479`	`if (!(tup = SearchSysCacheTuple(OPRNAME,`
`475`	`480`	`PointerGetDatum(op),`
`476`	`481`	`ObjectIdGetDatum(arg1),`
Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.1.1.1 1996/07/09 06:21:40 scrappy Exp $`
	`11`	`+ * $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.2 1996/07/19 07:24:09 scrappy Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -617,7 +617,11 @@ make_const(Value *value)`
`617`	`617`
`618`	`618`	`/* null const */`
`619`	`619`	`con = makeConst(0, 0, (Datum)NULL, TRUE, 0, FALSE);`
	`620`	`+#ifdef NULL_PATCH`
	`621`	`+ return con;`
	`622`	`+#else`
`620`	`623`	`return NULL /con/;`
	`624`	`+#endif`
`621`	`625`	`}`
`622`	`626`	`}`
`623`	`627`