8.0 이전 MySQL 버전에서 누적 합계를 계산하는 방법은 무엇입니까?

SELECT IF(@prev_id = c.id AND @prev_day = c.day,
         @cumtotal := @cumtotal + c.amount,
         @cumtotal := c.amount) AS cumulative_total
     , @prev_id  := c.id  AS `id`
     , @prev_day := c.day AS `day`
     , c.hr
     , c.amount AS `amount'
  FROM ( SELECT @prev_id  := NULL
              , @prev_day := NULL
              , @subtotal := 0
       ) i
  JOIN (
         select id, day, hr, amount from
         ( //multiple joins on multiple tables)a
         left join
         (//unions on multiple tables)b
         on a.id=b.id
         ORDER BY 1,2,3
       ) c

SELECT d.id
     , d.day
     , d.hr
     , d.amount
     , d.cumulative_total
FROM (
       // query from above
     ) d