From: Jonathan Gardner <jgardner@jonathangardner.net>
To: Jodi Kanter <jkanter@virginia.edu>
To: Postgres SQL List <pgsql-sql@postgresql.org>
Subject: Re: duplicate dates
Date: Fri, 8 Aug 2003 08:29:36 -0700
Message-ID: <200308080829.37711.jgardner@jonathangardner.net> (raw)
In-Reply-To: <3F2A8DAE.4060003@virginia.edu>
References: <3F2A8DAE.4060003@virginia.edu>
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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
by. Note that date_part can give you interesting groupings (all the
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 the
from clause. You could also save the results in a temp table.
- --
Jonathan Gardner <jgardner@jonathangardner.net>
Live Free, Use Linux!
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Cc: jgardner@jonathangardner.net, jkanter@virginia.edu
Subject: Re: duplicate dates
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