Re: [HACKERS] Re: [SQL] MAX() of 0 records.

At 21:21 9/07/00 -0400, Tom Lane wrote:
>
>> Sounds perfect to me...
>
>Note that it would not meet your expectation that

This seems OK; the 'update...from' syntax does also seemingly implies that
the rows affected will only be those rows that match the predicate, so your
interpretation is probably more in keeping with intuitive expectation.

>
>... at least not without some kind of outer-join support too. With
>an inner join, t1 tuples not matching any t2 tuple wouldn't be modified
>at all.

This sounds good, but even when OJ come along, I can't see how I would get
the same behaviour as:

update t1 set f2=(Select Count(*) from t2 where t2.f1=t1.f1)
where t1.f1 = 2

since in an OJ, count(*) will, I think, always be at least 1.

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