Re: Implicit constraints in a view
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 10 Nov 2006 00:44:42 GMT
Message-ID: <_XP4h.285972$5R2.2846_at_pd7urf3no>
Date: Fri, 10 Nov 2006 00:44:42 GMT
Message-ID: <_XP4h.285972$5R2.2846_at_pd7urf3no>
If I may make a twist on the recent view discussions here and in the other busy thread, I'd like to ask this question: what do the common SQL products do in the following case?
Suppose we have S1 equal to an empty relation with heading {S#, SNAME} with S# as (candidate) key and S2 equal to the same relation and then we define view S as S1 UNION S2. Then we insert the value {'S1', 'X'} into S1 and the value {'S1', 'Y'} into S2. Then we select view S.
(I'm also curious if the SQL standard has anything to say about this.)
p Received on Fri Nov 10 2006 - 01:44:42 CET