How to calculate cumulative average

Question

I want to calculate cumulative average of my data.

in my query i get sum value for every date now.But I am confused How to calculate calculate cumulative average.

my query

SELECT 
  u.id,
  (SUM(m.protein)),
  DATE(FROM_UNIXTIME(u.create)) AS Cdate,
  goal.what,
  goal.value 
FROM
  `meal` AS m,
  `user_history` AS u 
LEFT JOIN goal 
    ON goal.what = 'Protein' 
    AND goal.user_id = 48 
WHERE u.meal_id = m.id 
  AND u.user_id = 48 
GROUP BY DATE(FROM_UNIXTIME(u.create))

Here I get the sum value by sum(m.protein) but i want here cumulative average

Answer 1

SET @csum=0;
SELECT 
  u.id,
  (SUM(m.protein)) as sum1,
  (@csum := @csum + sum1) as CSUM,
  DATE(FROM_UNIXTIME(u.create)) AS Cdate,
  goal.what,
  goal.value 
FROM
  `meal` AS m,
  `user_history` AS u 
LEFT JOIN goal 
    ON goal.what = 'Protein' 
    AND goal.user_id = 48 
WHERE u.meal_id = m.id 
  AND u.user_id = 48 
GROUP BY DATE(FROM_UNIXTIME(u.create))