Display correct cumulative_sum value using Mysql - mysql

Question

I used the mysql query below.
Select MONTHNAME(t.date) as month, YEAR(t.date) as iyear, t.income,
t.subincome, t.ssubincome, sum(rupees) as amount,
COALESCE((SELECT
SUM(x.rupees)
FROM house_details x WHERE x.id < t.id), '-') AS progressive_total,
(SELECT SUM(x.rupees)
FROM house_details x WHERE x.id <= t.id
group by MONTH(t.date)) AS cumulative_sum
FROM house_details t
WHERE YEAR(t.date) = YEAR(CURRENT_DATE()) AND t.subincome = "Garbage tax"
GROUP BY MONTH(t.date) order by t.id
and got the value below:
month iyear income subincome amount progressive_total cumulative_sum
January 2017 Taxes Garbage tax 385 - 125
February 2017 Taxes Garbage tax 890 125 1015
March 2017 Taxes Garbage tax 200 1015 1215
April 2017 Taxes Garbage tax 250 1215 1465
May 2017 Taxes Garbage tax 270 1465 1735
The cumulative_sum in first row shows wrongly as 125.It should show as 385.I want to display the correct cumulative_sum group by month.
SQL Fiddle: http://sqlfiddle.com/#!9/c7b979/1/0

Answer 1

First thing you need to update is remove comparisons on id because id is not sequential as date January record can come after march or nay month record so this may result as invalid calculations. Second thing for cumulative sum and progressive total you need to do this when your main query is executed with GROUP BY like
SELECT *,
COALESCE((SELECT SUM(x.rupees) FROM house_details x WHERE MONTH(x.date) < t1.month AND x.subincome = "Garbage tax" ), 0) AS progressive_total,
(SELECT SUM(x.rupees) FROM house_details x WHERE MONTH(x.date) <= t1.month AND x.subincome = "Garbage tax" ) AS cumulative_sum
FROM (
SELECT MONTHNAME(t.date) AS `monthname`,
MONTH(t.date) `month`,
YEAR(t.date) AS iyear,
t.income,
t.subincome,
t.ssubincome,
SUM(rupees) AS amount
FROM house_details t
WHERE YEAR(t.date) = YEAR(CURRENT_DATE()) AND t.subincome = "Garbage tax"
GROUP BY MONTH(t.date)
ORDER BY t.date
) t1
Demo