在mysql查询中条件为SUM或SUBTRACTION

Question

I want to do SUM or SUBTRACTION upon certain condition within mysql query. This is : SQLFiddle

Condition:

if ce_type is IN OR NULL then add payment_amount in a variable

and

if ce_type is OUT then i want to subtract payment_amount from that variable.

I tried it with this query. But, I don't know how to put condition here.

SELECT SUM(payment_amount) as payment_amount
FROM customer_payment_options
WHERE (real_account_id='11' AND real_account_type='HQ')
AND company_id='1'

Answer 1

You just want conditional aggregation, if I understand correctly:

SELECT SUM(CASE WHEN ce_type = 'IN' or ce_type is NULL then payment_amount
                WHEN ce_type = 'OUT' then - payment_amount
           END) as payment_amount
FROM customer_payment_options
WHERE real_account_id = '11' AND real_account_type = 'HQ' AND company_id = '1';

Answer 2

IF ce_type can only have the values NULL , IN and OUT , the following statement does the job.

SELECT SUM(IF(ce_type = 'IN' OR ce_type is NULL,payment_amount,-payment_amount)) as payment_amount
FROM customer_payment_options
WHERE (real_account_id='11' AND real_account_type='HQ')
AND company_id='1';

Answer 3

SELECT SUM(
    CASE WHEN ce_type IS NULL THEN 1 ELSE 
        CASE ce_type WHEN 'IN' THEN 1 ELSE -1 END 
    END 
    * payment_amount) as payment_amount
FROM customer_payment_options
WHERE (real_account_id='11' AND real_account_type='HQ')
AND company_id='1'

Answer 4

You can use IF() to change it conditionally:

SELECT SUM(IF(ce_type = "OUT", -1 * payment_amount, payment_amount)) as payment_amount
FROM customer_payment_options
WHERE (real_account_id='11' AND real_account_type='HQ')
AND company_id='1'