Subject: GROUP BY [Was: SELECT]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




From: "Ron Piggott (PHP)" <ron.php@xxxxxxxxxxxxxxxxxx>
Reply-To: ron.php@xxxxxxxxxxxxxxxxxx
To: PHP DB <php-db@xxxxxxxxxxxxx>
Content-Type: text/plain
Date: Sat, 10 Dec 2005 20:04:28 -0500
Message-Id: <1134263069.3515.86.camel@xxxxxxxxxxxxxxxxxxxxx>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: SELECT

I am trying to put together a SELECT syntax.  I am querying a response
database and I only want to obtain each user's name once even if they
have given more than 1 response.

$query="SELECT * FROM  conversation_table WHERE conversation_reference =
$conversation_currently_displayed";

... Add "GROUP BY conversation_user_id" or whatever column you use to identify the user.

http://dev.mysql.com/doc/refman/5.0/en/select.html

Note that GROUP BY comes *before* any ORDER BY in your select (which you aren't doing). By default, MySQL will order by the grouped columns initially. Other databases you'd have to include the GROUP BY column(s) in the select * statement, but MySQL allows you to do this with non-selected fields as well.

Then spend some time on the MySQL site looking at the 'aggregate functions' area now you've grouped the results - you'll find some useful stuff you can do once that's happened :

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html

Cheers - Neil

--
PHP Database Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php


[Index of Archives]     [PHP Home]     [PHP Users]     [Postgresql Discussion]     [Kernel Newbies]     [Postgresql]     [Yosemite News]

  Powered by Linux