Case in where mysql not working

Question

SELECT SUM(amount) as tdb 
FROM (`v_ledger_details`) 
WHERE `debit_credit` = 'DB' 
AND `CASE` WHEN transaction_type_id IN(4,5) 
           THEN billDate < "2016-06-01" 
           ELSE postingDate < "2016-06-01" 
     END 
AND accountId = '944'

what is worong with the above query. i need the case claues in where but that query give me error.

Answer 1

Don't use case in a where clause. Normally only use it in select clauses. And then don't backtick the case keyword

SELECT SUM(amount) as tdb 
FROM v_ledger_details
WHERE `debit_credit` = 'DB' 
AND accountId = '944'
AND 
(
    (transaction_type_id IN (4,5) and billDate < '2016-06-01') OR
    (transaction_type_id NOT IN (4,5) AND postingDate < '2016-06-01')
)