Re: Primary Key Theory Question

Em Sun, 28 Mar 2004 21:53:07 +0000, Ben escreveu:

> _how_ does one
> generate a surrogate key that is a) unique and b) usable from an
> application programmer's point of view.

        For the programmers, SEQUENCEs are about as good as it gets. PostgreSQL's serial is also good. I am not familiar with SQL Servers' identity...

        Now obviously any surrogate key alone *is* a recipe for disaster. That's why one needs still to implement uniqueness constraints for the natural candidate keys. Surrogates are only to keep programmers and users from whining about composite keys.

> sequences and Identity columns are great from an application developers
> point of view because you have easy access to the key of a newly created
> record.

        Sequences are nice too, SELECT sequence.nextval FROM dual;

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