From: Jean-Luc Lachance <jllachan@nsd.ca>
To: Dan MacNeil <dan@ltc.org>
To: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: count(boolean)
Date: Mon, 20 May 2002 12:07:37 -0400
Message-ID: <3CE91F49.DC7B73C8@nsd.ca> (raw)
References: <JGEPJNMCKODMDHGOBKDNAELLCOAA.joel@joelburton.com>
<001d01c1ff3f$d7d86470$b11a9318@prometheus>
<3CE9117F.183B58EE@nsd.ca>
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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To: pgsql-sql@postgresql.org
Cc: jllachan@nsd.ca, dan@ltc.org
Subject: Re: count(boolean)
In-Reply-To: <3CE91F49.DC7B73C8@nsd.ca>
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