Help writing a SQL subquery

[eluser]danmontgomery[/eluser]
Ah... You didn't say that.

Code:

SELECT users.*, SUM(`shift_length`) AS shift_length FROM (`overtime_assigned`)
JOIN users ON users.user_ID = overtime_assigned.user_ID
WHERE users.user_ID IN ( SELECT users.user_ID FROM overtime_list
JOIN `users` ON `users`.`user_ID` = `overtime_list`.`user_ID`
JOIN `stations` ON `users`.`station_ID` = `stations`.`station_ID`
JOIN `postcode_db` ON `users`.`postcode_ID` = `postcode_db`.`postcode_ID`
WHERE `date` = '.$date.' AND `type` = '.$type.' AND `day` = '.$day.'
GROUP BY `postcode_db`.`postcode_ID`)
GROUP BY users.user_ID

Is the users table necessary in the subquery? If at all possible I would eliminate that join (you can select the user_ID from overtime_list table, for example)