Обсуждение: Where clause

Hello, 

I have a table called tracking, with a contactid varchar, click bool,
view bool and cid varchar.

I would like to put the following into one single query if possible:

// Number of clicks
select cid,count(distinct contactid) from tracking where click =
true group by cid; 

// Number of views
select cid,count(distinct contactid) from tracking where view =
true group by cid; 

I guess I have to put where (click = true or view = true) - and
differentiate them in the SELECT target.. ?


Many thanks for any input, 

Mike

am  Tue, dem 26.06.2007, um 10:24:05 +0200 mailte Michael Landin Hostbaek folgendes:
> Hello, 
> 
> I have a table called tracking, with a contactid varchar, click bool,
> view bool and cid varchar.
> 
> I would like to put the following into one single query if possible:
> 
> // Number of clicks
> select cid,count(distinct contactid) from tracking where click =
> true group by cid; 
> 
> // Number of views
> select cid,count(distinct contactid) from tracking where view =
> true group by cid; 
> 
> I guess I have to put where (click = true or view = true) - and
> differentiate them in the SELECT target.. ?

*untested*

select cid, sum(case when click = true then 1 else 0 end), sum(case when
view = true then 1 else 0 end) from ...


Andreas
-- 
Andreas Kretschmer
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A. Kretschmer (andreas.kretschmer) writes:
> *untested*
> 
> select cid, sum(case when click = true then 1 else 0 end), sum(case when
> view = true then 1 else 0 end) from ...
> 

Thanks, but I need the DISTINCT contactid - I don't want the same
contactid counted twice.

Mike

Στις Τρίτη 26 Ιούνιος 2007 12:44, ο/η Michael Landin Hostbaek έγραψε:
> A. Kretschmer (andreas.kretschmer) writes:
> > *untested*
> >
> > select cid, sum(case when click = true then 1 else 0 end), sum(case when
> > view = true then 1 else 0 end) from ...
>
> Thanks, but I need the DISTINCT contactid - I don't want the same
> contactid counted twice.
>

Something like

SELECT distinct cid,(select count(distinct t1.contactid) from tracking t1
where t1.view and t1.cid=tglob.cid) as countviews,(select count(distinct
t2.contactid) from tracking t2 where t2.click and t2.cid=tglob.cid) as
countclicks from tracking tglob;

?
> Mike
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend

--
Achilleas Mantzios

Michael Landin Hostbaek wrote:
> A. Kretschmer (andreas.kretschmer) writes:
>> *untested*
>>
>> select cid, sum(case when click = true then 1 else 0 end), sum(case when
>> view = true then 1 else 0 end) from ...
>>
> 
> Thanks, but I need the DISTINCT contactid - I don't want the same
> contactid counted twice.

... GROUP BY cid

--   Richard Huxton  Archonet Ltd

Michael Landin Hostbaek skrev:
> Hello, 
> 
> I have a table called tracking, with a contactid varchar, click bool,
> view bool and cid varchar.
> 
> I would like to put the following into one single query if possible:
> 
> // Number of clicks
> select cid,count(distinct contactid) from tracking where click =
> true group by cid; 
> 
> // Number of views
> select cid,count(distinct contactid) from tracking where view =
> true group by cid; 

Untested, not the cleverest formulation, but something like this should
work:

SELECT * FROM
(
select cid,count(distinct contactid) from tracking where click =
true group by cid
) c1
FULL OUTER JOIN
(
select cid,count(distinct contactid) from tracking where view =
true group by cid
) c2
USING (cid);

news.gmane.org (nis) writes:
> SELECT * FROM
> (
> select cid,count(distinct contactid) from tracking where click =
> true group by cid
> ) c1
> FULL OUTER JOIN
> (
> select cid,count(distinct contactid) from tracking where view =
> true group by cid
> ) c2
> USING (cid);


That did the trick!

Many thanks, 

Mike