Re: Network Example: Sibling of Opposite Gender
From: Tonkuma <tonkuma_at_jp.ibm.com>
Date: 30 Dec 2006 04:03:16 -0800
Message-ID: <1167480196.286083.36890_at_48g2000cwx.googlegroups.com>
Date: 30 Dec 2006 04:03:16 -0800
Message-ID: <1167480196.286083.36890_at_48g2000cwx.googlegroups.com>
Lennart wrote:
> Minor note: "OR gender IS NULL" is not necessary. You can define the
> constraint gender_value as CHECK(gender IN ('male', 'female')).
> gender_value must not evaluate to FALSE, and in the case of null it is
> evaluated to null, which is - sort of - ok.
>
> /Lennart
Thak you, Lennart.
Received on Sat Dec 30 2006 - 13:03:16 CET