From: "Josh Berkus" <josh@agliodbs.com>
Subject: Re: Date Problem
To: "pauLSiew" <paul@mqplayharder.com>, pgsql-sql@postgresql.org
Date: Fri, 22 Feb 2002 08:51:55 -0800
Message-ID: <web-700688@davinci.ethosmedia.com>
In-Reply-To: <a54b0m$2qvq$1@jupiter.hub.org>
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Paul,

> I'm using pgsql with php, and my query below will retrieve employee's
> monthly sales total,
> 
> "select sum(salesTotal) from ocf where employeeNo='0123' AND
>  orderDate like
> '%$month $year %'" // i put % infront to ignore day, and % at the
>  back to
> ignore the time (because i'm using timestamp with timezone), then i
>  shall
> get particular month's records.

The main problem is that you are treating the TIMESTAMP field like it
 is text.  It is not.  You cannot use comparitors designed for text
 parsing (such as "LIKE '%xxxyyy%') on TIMESTAMPs and get reliable
 results.

Instead, use functions designed for TIMESTAMPs:
http://www.postgresql.org/idocs/index.php?functions-datetime.html

For example, you could:
SELECT ... WHERE EXTRACT(month FROM orderdate) = $month AND
 EXTRACT(year FROM orderdate) = $year;
... but there are a few ways you can answer this question.  Read the
 documentation page; better yet, buy and read a PostgreSQL book.

-Josh Berkus

P.S. In the future, questions of this type are more appropriate for the
 NOVICE list.  The SQL list is more for the
 "how-do-I-get-this-insanely-complex-query-to-perform" type.


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