Re: group by day

am Thu, dem 24.05.2007, um 14:49:47 -0400 mailte Edward W. Rouse folgendes:
> I have an audit table that I am trying to get a count of the number of distinct
> entries per day by the external table key field. I can do a
>
> select count(distinct(id)) from audit where timestamp >= '01-may-2007'
>
> and get a total count. What I need is a way to group on each day and get a
> count per day such that the result would be something like
>
> date count
> 01-may-2007 107
> 02-may-2007 215
> 03-may-2007 96
> 04-may-2007 0
>
>
> I would prefer the 0 entries be included but can live without them. Thanks.

You are searching for GROUP BY.

A simple example:

test=*# select * from foo;
ts | val
---------------------+-----
2007-05-01 08:00:00 | 10
2007-05-01 08:00:00 | 20
2007-05-02 10:00:00 | 20
2007-05-02 11:00:00 | 30
(4 rows)

Time: 1.079 ms
test=*# select ts::date, sum(val) from foo group by 1;
ts | sum
------------+-----
2007-05-02 | 50
2007-05-01 | 30
(2 rows)

Andreas
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Andreas Kretschmer
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