From: Jonathan Gardner <jgardner@jonathangardner.net>
To: Jodi Kanter <jkanter@virginia.edu>,
	Postgres SQL List <pgsql-sql@postgresql.org>
Subject: Re: duplicate dates
Date: Fri, 8 Aug 2003 08:29:36 -0700
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On Friday 01 August 2003 08:56, Jodi Kanter wrote:
> I have one table that has a date/time field in it. I'd like to identify
> the records in the database where the date/time fields are the same. How
> can I do this? Do I need to create a view or temp table? Is there a way
> to run through one table multiple times.

SELECT date_trunc('month', date_column), ...
GROUP BY date_trunc('month', date_column)
HAVING count(primary_key) > 1;

Replace date_trunc('month', date_column) with whatever you want to group it=
=20
by. Note that date_part can give you interesting groupings (all the=20
Decembers, all the 1st of the months, all the Fridays, etc...)

If you want to run through it several times, you can have a sub-select in t=
he=20
from clause. You could also save the results in a temp table.

- --=20
Jonathan Gardner <jgardner@jonathangardner.net>
Live Free, Use Linux!
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