Manfred Koizar wrote:
> On Tue, 19 Jul 2005 11:51:51 +0100, Richard Huxton <dev@archonet.com>
> wrote:
>
>>You could get away with one query if you converted them to left-joins:
>>INSERT INTO ...
>>SELECT * FROM upload LEFT JOIN ... WHERE f3 IS NULL
>>UNION
>>SELECT * FROM upload LEFT JOIN ... WHERE f4 IS NULL
>
>
> For the archives: This won't work. Each of the two SELECTs
> eliminates rows violating one of the two constraints but includes rows
> violating the other constraint. After the UNION you are back to
> violating both constraints :-(
Couldn't you use "INTERSECT" then? To only get the rows that *both*
queries return?
John
=:->
>
> Servus
> Manfred
>
>
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