I have this query and I need to add a where clause (`WHERE order_number = 1`) on my first query, but it's not working.

```
SELECT 
    last_name,
    first_name,
    total,
    pickup_date,
    MPU.salary,
    MTU.materials,
    OFU.otherfee
FROM
    finished AS FD
        INNER JOIN
    (SELECT 
        order_number, (SUM(salary * hours_worked)) AS 'salary'
    FROM
        manpower_used
    GROUP BY order_number) AS MPU ON FD.order_number = MPU.order_number
        INNER JOIN
    (SELECT 
        order_number, (SUM(qty * price)) AS 'materials'
    FROM
        materials_used
    GROUP BY order_number) AS MTU ON FD.order_number = MTU.order_number
        INNER JOIN
    (SELECT 
        order_number,
            (SUM(overtime_fee + stair_fee + toll_fee)) AS 'otherfee'
    FROM
        other_fees
    GROUP BY order_number) AS OFU ON FD.order_number = OFU.order_number

```

Thank you!