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 |  102007-05-01 08:00:00 |  202007-05-02 10:00:00 |  202007-05-02
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 |  502007-05-01 |  30
(2 rows)


Andreas
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Andreas Kretschmer
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