How to Calculate Cumulative Sum-Running Total in MySQL
From: How to Calculate Cumulative Sum-Running Total in MySQL - PopSQL How to Calculate Cumulative Sum-Running Total in MySQL Let's say for our MySQL DVD rental database, we want to see a hockey stick graph of our cumulative rentals by day. First, we'll need a table with a day column and a count column: SELECT date (rental_date) as day , count (rental_id) as rental_count FROM rental GROUP BY day ; day | rental_count -----------+-------------- 2005-05-24 | 8 2005-05-25 | 137 2005-05-26 | 174 2005-05-27 | 166 2005-05-28 | 196 Then we use this to do our cumulative totals. Before MySQL version 8 you can use variables for this: SELECT t.day, t.rental_count, @running_total:=@running_total + t.rental_count AS cumulative_sum FROM ( SELECT date (rental_date) as day , count (rental_id) as rental_count FROM rental GROUP BY day ) t JOIN ( SELECT @running_total:= 0 ) r ORDER BY t.day; day | rental_count | cumulative_sum -------