Question

Really stumped here, so any advice would be much appreciated please.

I in the clients table, I have the following records for the client with ID = 257:

SELECT ref, ID, client_name, data_1 FROM clients WHERE ID = 257

+------+-----+-------------+--------+
| ref  | ID  | client_name | data_1 |
+------+-----+-------------+--------+
| 1123 | 257 | Client257   | 0      |
| 1124 | 257 | Client257   | 163    |
+------+-----+-------------+--------+

Now, if I add a simple MAX() to the ref field, I get:

SELECT MAX(ref), ID, client_name, data_1 FROM clients WHERE ID = 257

+------+-----+-------------+--------+
| ref  | ID  | client_name | data_1 |
+------+-----+-------------+--------+
| 1124 | 257 | Client257   | 0      |
+------+-----+-------------+--------+

I should get:

+------+-----+-------------+--------+
| ref  | ID  | client_name | data_1 |
+------+-----+-------------+--------+
| 1124 | 257 | Client257   | 163    |
+------+-----+-------------+--------+

Can anyone explain this please? And what should I do to get the desired result?

EDIT:

Added the output of SHOW CREATE TABLE clients as requested by @Ilion:

CREATE TABLE `clients` (
 `ref` int(11) unsigned NOT NULL AUTO_INCREMENT,
 `ID` int(11) unsigned NOT NULL,
 `client_name` varchar(75) DEFAULT NULL,
 `data_1` int(11) unsigned NOT NULL DEFAULT '0',
 `last_updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 UNIQUE KEY `ref` (`ref`)
) ENGINE=MyISAM AUTO_INCREMENT=1135 DEFAULT CHARSET=utf8

Answer 1

does this help?

SELECT ref, ID, client_name, data_1 FROM clients WHERE ID = 257 and ref in
    (select max(ref) from clients WHERE ID = 257)