Untitled

SELECT *
FROM
        (SELECT
                bc.user_id,
                u.login_name,
                bo.total_balance,
                'charge' as charge_or_payment,
                type,
                sum(amount)
        FROM bill_charges bc JOIN
        users u USING (user_id) JOIN
        v_bill_overviews bo using (user_id)
        WHERE bc.creation_tsz >= '2010.04.01' and bc.creation_tsz < '2010.05.01'
        GROUP BY 1, 2, 3, 4,5
UNION
        SELECT
                bp.user_id,
                u.login_name,
                bo.total_balance,
                'payment' as charge_or_payment,
                type,
                sum(amount)*-1
        FROM
                 bill_payments bp JOIN
                 users u using (user_id) JOIN
                 v_bill_overviews bo using (user_id)
        WHERE
                bp.creation_tsz >= '2010.06.01' AND bp.creation_tsz < '2010.07.01' AND
                type LIKE '%_refund'
        GROUP BY 1, 2, 3, 4, 5
        ) AS biff
order by user_id;