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Posted by Robson on 10/07/05 10:04
Thanks very much Stephan & ZeldorBlat
"ZeldorBlat" <zeldorblat@gmail.com> a ιcrit dans le message de news:
1128654967.322008.175270@g44g2000cwa.googlegroups.com...
> Stefan is right. In most databases, a primary key constraint is the
> equivalent of a unique index. The main differences are that you can
> only have one primary key constraint per table and the columns involved
> cannot allow nulls.
>
> Also many (most) databases also create the primary key index as
> clustered -- provided there are no other clustered indexes on the table
> (since only one per table is allowed).
>
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