Re: count distinct

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Fri, 25 Jun 2004 17:08:59 -0700
Message-ID: <1088208567.514545@yasure>

Andy Hassall wrote:

> On Wed, 23 Jun 2004 22:26:23 -0700, Daniel Morgan <damorgan_at_x.washington.edu>
> wrote:
>
>

>>Romeo Olympia wrote:
>>
>>
>>>Uh, why not this???
>>>
>>>select count(distinct column1), count(distinct column2), 
>>>count(distinct column3), count(distinct column4)
>>>from mytable;
>>
>>Because it is totally unnecessary.
>>http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/statements_103a.htm#2065826

>
>
> Why is it unnecessary? Aggregate functions can have DISTINCT applied to the
> column they're aggregating, which would do what the OP is asking for. And this
> is different from the SELECT level DISTINCT clause you've linked to.
>
> http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/functions26a.htm#82699
>
> --
> Andy Hassall <andy_at_andyh.co.uk> / Space: disk usage analysis tool
> http://www.andyh.co.uk / http://www.andyhsoftware.co.uk/space

The quetion is whether you want a single value ... the count of distinct records or the count in four columns of distinct values.

My interpretation of the question was the former and thus the four separate counts unnecessary. Apparently my interpretation was incorrect.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
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Received on Fri Jun 25 2004 - 19:08:59 CDT