การ Query หลายๆเงื่อนไขแต่จบ กับการ Query ออกมาทีละเงื่อนไขแล้วนำค่าที่ได้มาวนลูปคำนวณ Query ใหม่ อันไหนดีกว่ากันครับ

SELECT
	*,
	CASE
		WHEN subQuery1.paymentDay != '' AND subQuery1.paymentDay IS NOT NULL AND subQuery1.paymentDay > 0
			THEN ROUND( (( ( 27 * 12 ) / DAYOFYEAR( CONCAT( YEAR ( NOW( ) ), '-12-31' ) ) ) * subQuery1.area * subQuery1.paymentDay ),4 )
			ELSE ROUND( (( ( 27 * 12 ) / DAYOFYEAR( CONCAT( YEAR ( NOW( ) ), '-12-31' ) ) ) * subQuery1.area * 11 ),4 )
	END AS paymentPrice
FROM
	(
SELECT
	units.unit_id,
	addresses.address_id,
	addresses.address_name,
	addresses.area,
	addresses.transfer_date,
	addresses.transfer_status,
	SUBSTRING_INDEX( SUBSTRING_INDEX( addresses.transfer_date, '/', 2 ), '/', - 1 ) AS transferDay,
	DAY ( LAST_DAY( '2018-08-01' ) ) AS dayInMonth,
CASE
	
	WHEN addresses.transfer_date != '' 
	AND addresses.transfer_date IS NOT NULL THEN
CASE

WHEN SUBSTRING_INDEX( addresses.transfer_date, '/', - 1 ) = '2016' 
	AND SUBSTRING_INDEX( addresses.transfer_date, '/', 1 ) = '07' THEN
		SUBSTRING_INDEX( SUBSTRING_INDEX( addresses.transfer_date, '/', 2 ), '/', - 1 ) - 1 ELSE NULL 
END ELSE NULL 
	END AS paymentDay,
	central_bill.central_bill_id,
	central_bill.MONTH,
	central_bill.YEAR,
	central_bill.price_total,
	central_bill.send,
	central_bill.STATUS,
	central_bill.paydate,
	central_bill.CODE,
	central_bill.code_rc 
FROM
	units
	INNER JOIN addresses ON units.address_id = addresses.address_id 
	AND addresses.transfer_status = '0' 
	AND addresses.building_id = '7'
	LEFT JOIN central_bill AS central_bill ON units.unit_id = central_bill.unit_id 
	AND central_bill.MONTH = '7' 
	AND central_bill.YEAR = '2019' 
) AS subQuery1