gistfile1.txt

SELECT 
	contract_id,
	date,
	due_date,
	SUM(rental) as rental,
	SUM(advance_rental)  as advance_rental,
	SUM(security_deposit)  as security_deposit,
	SUM(surcharge)  as surcharge,
	SUM(others)  as others,
	unit_id
FROM (
	SELECT
		a.contract_id as contract_id,
		a.date,
		a.due_date,
		IF(b.charges_type = 1,b.amount,0) as rental,
		IF(b.charges_type = 3,b.amount,0) as advance_rental,
		IF(b.charges_type = 4,b.amount,0) as security_deposit,
		IF(b.charges_type = 5,b.amount,0) as surcharge,
		IF(b.charges_type = 6,b.amount,0) as others,
		IF(b.unit_id is null,(
				SELECT cd.unit_id FROM contract_details cd where cd.header_id = a.contract_id limit 1
		),b.unit_id) as unit_id
	FROM property_charges_headers as a
	INNER JOIN property_charges_details as b on a.id = b.header_id
	WHERE
		YEAR(a.date) = 2019
		and MONTH(a.date) = 4
		and a.status = "Approved"
		and b.charges_type in (1,3,4,5,6)
	ORDER BY a.contract_id
) as t1
GROUP BY unit_id
ORDER BY contract_id