Message-ID: <3CE91F49.DC7B73C8@nsd.ca>
Date: Mon, 20 May 2002 12:07:37 -0400
From: Jean-Luc Lachance <jllachan@nsd.ca>
MIME-Version: 1.0
To: Dan MacNeil <dan@ltc.org>, pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: count(boolean)
References: <JGEPJNMCKODMDHGOBKDNAELLCOAA.joel@joelburton.com>
	<001d01c1ff3f$d7d86470$b11a9318@prometheus>
	<3CE9117F.183B58EE@nsd.ca>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Actually, "count" should be "sum"

SELECT
  question_id AS id,
  sum( case when value then 1 else 0 end) as count_true,
  sum( case when value then 0 else 1 end) as count_false
FROM
  answers_boolean
GROUP BY
  question_id;


I wrote:

> 
> Dan,
> 
> Try:
> 
> SELECT
>   question_id AS id,
>   count( case when value then 1 else 0 end) as count_true,
>   count( case when value then 0 else 1 end) as count_false
> FROM
>   answers_boolean
> GROUP BY
>   question_id;
> 
> jll
> 
> Dan MacNeil wrote:
> >
> > I have a table answers_boolean:
> >
> >  question_id   | integer   | not null
> >  evaluation_id | integer   | not null
> >  value             | boolean |
> >
> > I'd like output in the form:
> >
> > question_id,  count_true, count_false
> >
> > ....where count_true is the number of questions answered "true"
> >
> > SELECT
> >     question_id AS id, value AS val , count(value) AS cnt
> > FROM
> >      answers_boolean
> > GROUP BY
> >      question_id,value;
> >
> > gives me:
> >  id | val | cnt
> > ----+-----+-----
> >   2 | f   |   3
> >   2 | t   |   3
> >   3 | f   |   2
> >   3 | t   |   4
> >
> > ...which is sorta what I want.
> >
> > I've looked through the docs & archive but haven't found the answer.
> >
> > TIA
> >
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