Re: [Hibernate] generated field as part of composite key

[Chris W. <cwi...@op...>]

On Fri, 2002-09-27 at 19:15, Gavin King wrote:
> Thats what happens when you write emails at 3 am. I meant to express my
> interest in the fact that MS SQL can generate values that are unique, not
> for the whole table, but only for other rows with the same values in the
> other primary key fields. I never knew something like that existed...

IDENTITY fields in MS SQL (and Sybase, for that matter) are very simple:
there can be only one IDENTITY field per table, and every INSERT is
guaranteed to generate a unique value for that field. Beyond that, you
can use them however you like -- they *can* (and frequently are) a
single primary key field, but that's not a requirement. 

Whether it's a good design to have an IDENTITY field as part of a
composite key is another discussion... :-)

Chris