| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Don Baccus <dhogaza(at)pacifier(dot)com> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: [HACKERS] check contraints incorrectly reject "null" |
| Date: | 1999-12-10 00:36:16 |
| Message-ID: | 10053.944786176@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Don Baccus <dhogaza(at)pacifier(dot)com> writes:
> According to Date, a check contraint should fail if the expression
> evaluates to false.
And SQL92 says:
A table check constraint is satisfied if and only if the specified
<search condition> is not false for any row of a table.
^^^^^^^^^
so they agree: a constraint that yields NULL should be considered
to pass. A tad nonintuitive, but who am I to argue...
I have fixed several bugs recently having to do with incorrect
evaluation of three-state boolean logic. I'll take care of this one.
regards, tom lane
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