Message-ID: <3AA51291.BA386B47@anpe.fr>
Date: Tue, 06 Mar 2001 17:38:41 +0100
From: patrick.jacquot@anpe.fr
Organization: anpe
MIME-Version: 1.0
To: pgsql-sql@postgresql.org
Subject: Re: Comparing dates
References: <20010306133323.A3880@josefine.ben.tuwien.ac.at>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Markus Fischer wrote:

> Hello,
>
> I've a SELECT statement on many joined Tabled and one of them has
> a date column called 'date_date'. When I fetch a date e.g.
> '02-03-2001', I get, say, 60 results back. When I now perform the
> same query with another date, lets take '03-03-2001', I get back
> about 70 results.
>
> When I now modify my query to get both results in one I write
>
> SELECT
>         ....
> FROM
>         ..
>         AND
>                 date_date >= '2001-03-02'
>         AND
>                 date_date <= '2001-03-03'
>         AND
>         ....
>
> I think I should get back the rows for both days, 60 + 70 makes
> 130 to me. But what I get back is even smaller then 60. I
> allready tried TO_DATE conversion, an OR construct but always
> the same result.
>
> Is there something special to know when comparing/working with
> date-datetypes ?
>
> kind regards,
>         Markus
>
> --
> Markus Fischer,  http://josefine.ben.tuwien.ac.at/~mfischer/
> EMail:         mfischer@josefine.ben.tuwien.ac.at
> PGP Public  Key: http://josefine.ben.tuwien.ac.at/~mfischer/C2272BD0.asc
> PGP Fingerprint: D3B0 DD4F E12B F911 3CE1  C2B5 D674 B445 C227 2BD0
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister command
>     (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)

ANDing restrictions makes them narrower.
If you want to broaden your selection, try  ORing the conditions
HTH
Patrick