Question

I need to combine my main query with a subquery:

Current query (which works):

SELECT *,(SELECT SUM(shift_length)FROM overtime_list
WHERE overtime_list.user_ID = users.user_ID AND overtime_list.date > '$totalovertimedays') AS overtime_total FROM availability_list
JOIN users ON users.user_ID = availability_list.user_ID
JOIN stations ON users.station_ID` = stations.station_ID
WHERE availability_list.date = '$date' AND type = '$type'
ORDER BY overtime_total ASC

($date and $type are vars filled in by PHP)

The query I want to insert this as a sub-query:

SELECT role_ID, GROUP_CONCAT(users_roles.role_ID) AS roles FROM users
JOIN users_roles ON users.user_ID = users_roles.user_ID
GROUP BY users.users_ID

I got this far – but I cant seem to get the GROUP BY to work, so it doesnt list them correctly:

SELECT *,(SELECT SUM(shift_length)FROM overtime_list
WHERE overtime_list.user_ID = users.user_ID AND overtime_list.date > '$totalovertimedays') AS overtime_total FROM availability_list
JOIN users ON users.user_ID = availability_list.user_ID
JOIN `stations` ON `users`.`station_ID` = `stations`.`station_ID`,
(SELECT role_ID, GROUP_CONCAT(users_roles.role_ID separator ', ') AS roles FROM users JOIN users_roles ON users.user_ID = users_roles.user_ID GROUP BY users.user_ID) AS roles
WHERE availability_list.date = '$date' AND type = '$type'
ORDER BY overtime_total ASC

availability_list table:

 +----------+---------+
 |  user_ID | user    |
 +----------+---------+
 |        1 |   Smith |
 +----------+---------+
 |        2 |   Jones |
 +----------+---------+
 |        3 |   Greg  |
 +----------+---------+

overtime_list table:

 +----------+----------------+------------+
 |  date    | shift_length   |   user_ID  |
 +----------+----------------+------------+
 |  1/1/11  |   5            |      1     |
 +----------+---------+------+------------+
 |  1/2/11  |   5            |      2     |
 +----------+---------+------+------------+
 |  1/6/11  |   2            |      2     |
 +----------+---------+------+------------+
 |  1/8/11  |   5            |      1     |
 +----------+---------+------+------------+
 |  1/12/11 |   2            |      1     |
 +----------+---------+------+------------+

users_roles table:

 +----------+---------+
 |  user_ID | roles   |
 +----------+---------+
 |        1 |   Admin |
 +----------+---------+
 |        2 |   Staff |
 +----------+---------+
 |        2 |   Admin |
 +----------+---------+
 |        2 |   Super |
 +----------+---------+
 |        1 |   Other |
 +----------+---------+

So the result would be:

 +----------+---------+----------------------------+------------------+
 |  user_ID | user    |   roles                    |  overtime_total  |
 +----------+---------+----------------------------+------------------+
 |        1 |   Smith |    Admin, Other            |        12        |
 +----------+---------+----------------------------+------------------+
 |        2 |   Jones |    Staff, Admin, Super     |        7         |
 +----------+---------+----------------------------+------------------+
 |        3 |   Greg  |                            |  null (or zero)  |
 +----------+---------+----------------------------+------------------+

Answer 1

This should work –

SELECT users.*,
    SUM(overtime_list.shift_length) AS overtime_total,
    (SELECT GROUP_CONCAT(users_roles.role_ID) FROM users_roles WHERE users.user_ID = users_roles.user_ID) AS roles
FROM availability_list
INNER JOIN users
    ON users.user_ID = availability_list.user_ID
INNER JOIN `stations`
    ON `users`.`station_ID` = `stations`.`station_ID`
INNER JOIN overtime_list
    ON overtime_list.user_ID = users.user_ID
    AND overtime_list.date >= '$totalovertimedays'
WHERE availability_list.date = '$date'
AND type = '$type'
GROUP BY users.user_ID
ORDER BY overtime_total ASC