Subject: Can you match on (null)?

From: [email-masked]
Date: Fri, 20 Aug 93 15:23:48 +0200

Howdy all.

I must be missing something really simple.  I have a couple of
classes, where some attributes have nothing in it.  What Quel
statement (qualifier) do I use?

IE:

* retrieve (x.Login, x.Cdate, x.Edate) from x in Userdb
	where x.Edate = NULL \g

This returns nothing.  But if I do:

* retrieve (x.Login, x.Cdate, x.Edate) from x in Userdb \g

I get a lot of instances with:

...
-------------------------
| Login | Cdate | Edate |
-------------------------
| toby  | (null)| (null)|
-------------------------
...

If anyone can sched some light, please mail me directly as I am
not on the list.

Thanks.

--Toby.
--------------------------------------------------------------
|Tobias Weingartner  |    PGP2.x Public Key available at     |
| +41'01'254'7205    |   'finger [email-masked]'   |
--------------------------------------------------------------
%SYSTEM-F-ANARCHISM, the operating system has been overthrown

---

From: Ravi Lingam <[email-masked]>
Date: Sat, 21 Aug 93 0:03:33 EDT

Tobias Weingartner ([email-masked]) writes:
> This returns nothing.
Try this 
	where x.Edate ISNULL \g

to check if x.Edate is NULL and for NOT NULL try

	where x.Edate NOTNULL \g

I hope the above queries will solve you problem. 

-Ravi Lingam