Create a Cumulative Sum Column in MySQL

Question

I have a table that looks like this:

id   count
1    100
2    50
3    10

I want to add a new column called cumulative_sum, so the table wou

Answer 1

Sample query

SET @runtot:=0;
SELECT
   q1.d,
   q1.c,
   (@runtot := @runtot + q1.c) AS rt
FROM
   (SELECT
       DAYOFYEAR(date) AS d,
       COUNT(*) AS c
    FROM  orders
    WHERE  hasPaid > 0
    GROUP  BY d
    ORDER  BY d) AS q1