php - mysql query to get results from 2 tables by adding sum according to date -

i have query this, able data of both tables individually. concept want sum of amount according group month . 1 table can retrieve amount correctly, have sum of amounts both tables combined depending on month.

(select sum(amount) amount      , month(reciept_date) month      , year(reciept_date) year   sg_chool   academic_year = '2'   group month(reciept_date))   union   (select sum(amount_paid) amount       , month(reciept_date) month       , year(reciept_date) year   sg_fees   academic_year = '2'   group month(reciept_date)) 

try

select sum(temp.amount) amount, temp.month, temp.year ( (select sum(amount) amount      , month(reciept_date) month      , year(reciept_date) year   sg_chool   academic_year = '2'   group month(reciept_date))   union     (select sum(amount_paid) amount       , month(reciept_date) month       , year(reciept_date) year   sg_fees   academic_year = '2'   group month(reciept_date))  ) temp group temp.month;