Query query

From: Andrew Bell <acbell(at)iastate(dot)edu>
To: pgsql-novice(at)postgresql(dot)org
Subject: Query query
Date: 2001-11-27 19:00:55
Message-ID: 5.1.0.14.2.20011127125342.04b61900@acbell.mail.iastate.edu
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Hi,

You have all been so helpful, I'm going to bother you with another. Say
that you have a table with two categories. I want to do a *single* query
that shows the number of things in each of the primary category that match
a constraint and
the number of things that don't match that constraint.

Given the following table and the constraint cat2 = 1

cat1 | cat2

A 1
B 1
A 2
B 2
B 3
B 3

I want to generate output that looks like:

cat1 | count | count
A 1 1
B 1 3

Where the first 'count' represents the number of things that match the
constraint, and the second 'count' represents the number of things that
doesn't match the constraint.

Can this be done? If so how?

Thanks,

-- Andrew Bell
acbell(at)iastate(dot)edu

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