Max() Error, Why?

[JohnOP]

I'm re doing my private message system and im watching a video tutorial on it but have got this very strange error with the max() function

 

code

<?php
$sql = "SELECT `conversations`,`conversation_id`,
                         `conversations`,`conversation_subject`,
                  MAX(`conversations_messages`,`message_date`) AS `conversation_last_reply`
		  FROM `conversations`
		  LEFT JOIN `conversations_messages` ON `conversations`,`conversation_id` =                                    `conversations_messages`,`conversation_id`
		INNER JOIN `conversations_members` ON `conversations`,`conversation_id` = `conversations_members`,`conversation_id`
		WHERE `conversations_members`,`user_id` = {$id}
		AND `conversations_members`,`conversation_deleted` = 0
		GROUP BY `conversations`,`conversation_id`
		ORDER BY `conversation_last_reply` DESC";

 

All the fields and tables are correct and i get this error

 

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '`message_date`) AS `conversation_last_reply` FROM `conversations` LEFT J' at line 3

[mikosiko]

and when everything fail then is time to go back to the basic source of information

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

[kickstart]

Hi

 

Max shouldn't have 2 columns in it.

 

All the best

 

Keith

[JohnOP]

It doesn't one is the table name and one is the column from that table.

[kickstart]

Hi

 

Separate them with full stops. You might as well remove all the back tics as well (only needed when the column names are reserved words, and best to avoid that anyway)

 

All the best

 

Keith

[mikosiko]

the fact that you are using , instead of a dot to separate table name from column names is what is causing that error... and you have the same mistake in all others fields in your select

[JohnOP]

Oh its a dot and not a comma, thanks a lot that worked.