To my order-invoice example: there are not many choices, I know only three:
1) use NULL value and build proper query (x=? or x is null),
2) use dummy tupples and values (Marin's solution),
3) give up foreign key constraints on the database level and rely on the middle tier.
I have chosen 1).
Hoanui
--- On Tue 05/14, Tom Lane wrote:
> "Marin Dimitrov" writes:
> > don't use NULLs
>
> I agree with Marin. If you think you need x = NULL to act like x IS
> NULL, then you should rethink the way you are using NULL in your data
> design. You are really swimming against the tide of the way that SQL
> specifies NULL to work.
>
> regards, tom lane
>
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