Re: Multi column check constraint

From: Philip Lijnzaad <lijnzaad_at_ebi.ac.uk>
Date: 2000/05/22
Message-ID: <u7g0rb0zdu.fsf_at_o2-3.ebi.ac.uk>#1/1


>> alter table foobar add constraint exactly_one_null check (

>> (item_link_no is not null and voucher_id is not null) or
>> (item_link_no is null and voucher_id is not null) or
>> (item_link_no is not null and voucher_id is null));

Heinz> A simpler condition should be
Heinz> item_link_no is not null or voucher_id is not null

ah, yes, of course, I started from the (wrong) assumption that exactly one should be non-null, then added the 'both not null' as afterthought. Cheers,

                                                                      Philip

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Received on Mon May 22 2000 - 00:00:00 CEST

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