Re: [SQL] Agregate Problem?

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От Tom Lane
Тема Re: [SQL] Agregate Problem?
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Msg-id 10079.934732121@sss.pgh.pa.us
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Ответ на Re: [SQL] Agregate Problem?  (Herouth Maoz <herouth@oumail.openu.ac.il>)
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> At 17:01 +0300 on 15/08/1999, Len Morgan wrote:
>> SELECT itemno,sum(qty) FROM sales WHERE sale_date = 'now()::date'

This is invalid as it stands --- you need "GROUP BY itemno" because of
the aggregate function.  (IIRC, Postgres versions before 6.5 were a bit
lax about checking for that error.)

>> I would expect to get back zero rows if there were no sales today but I get
>> back 1.  Of course I also get back 1 row if I only sold 1 item.  Is this a
>> bug or a "feature?"

Herouth Maoz <herouth@oumail.openu.ac.il> writes:
> This is a correct behaviour when there is no GROUP BY. PostgreSQL does this
> in GROUP BY, too, unfortunately.

I believe we finally agreed that producing an empty row when there is a
GROUP BY is a bug (there was some debate about it).  I intend to change
that behavior for 6.6, but haven't actually done it yet...
        regards, tom lane


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