dtl4521 2010-12-28 10:31
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按间隔显示零的组

I'm trying to group a query by intervals in this way:

SELECT COUNT( * ) AS count, i.date
    FROM intervals i
    LEFT JOIN dtracker dt ON 
    i.date <= dt.date AND i.date + INTERVAL (NUMSEC) SECOND >= dt.date
    WHERE (SOME CONDITIONS)
    GROUP BY i.date

where I fill the table 'intervals' each time (cause intervals can change), and NUMSEC is changing as well depending of the intervals table.

Everything is working fine without 'WHERE', if there´s not results in some intervals, it shows 0 intervals. But if I put some conditions in 'WHERE' and there's no results, it doesn't show this interval anymore.

Seems like 'WHERE' clauses affects the whole query (it makes sense) but I need it to affect only to dtracker table. How I can do this?

Thanks a lot in advance.

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  • drfb52000 2010-12-28 10:37
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    Replace WHERE with another AND so that the conditions become part of the LEFT JOIN ... ON clause.

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