Re: I'm baffled by this one.

From: Neil Brown <neil_at_nmb.u-net.com>
Date: 1997/12/21
Message-ID: <349cf8ed.2385781@news.u-net.com>#1/1

On Sun, 21 Dec 1997 00:41:19 -0700, cellis_at_iol.ie (Chrysalis) wrote:

>I deduce that tablea(item) has a null value in at least one row.
>
>The query "select ... where item not in (select item ...)"
>is identical to "select ... where item <> ALL (select item ...)
>When the subquery eturns a null value the prdicate fails (null is not equal
>to null) and so no row is returned.
>
>Irritating but logical.
>

Understood. Thanks I'll investigate this.

Neil. Received on Sun Dec 21 1997 - 00:00:00 CST