mysql update column based on another updated column

Question

Note, this question is not same to the MySQL update column based on another column data manipulation

table order

| order_number | payment_amount | refund_amount | refund_status |
| 12           |  100           | 50            | 1             |

refund_status:

0: none refunded;
1: part refunded;
2: all refunded;

update order set refund_amount = refund_amount + 50, refund_status = CASE WHEN payment_amount = refund_amount + 50 THEN 2 ELSE 1 END where order_number = 12;
// refund_amount -> 100, refund_status ->1

Cannot get the right result (refund_amount -> 100, refund_status ->2).

But

update order set refund_amount = refund_amount + 50, refund_status = CASE WHEN payment_amount = refund_amount THEN 2 ELSE 1 END where order_number = 12;
// refund_amount -> 100, refund_status ->2

Can get the right result.

It seems update refund_status besed on the updated refund_amount , is it reliable?

Answer 1

use bracket every you use function case for system readable on your logic code.

update order
set refund_amount = (refund_amount + 50),
refund_status = (CASE WHEN payment_amount = refund_amount + 50 THEN 2 ELSE 1 END)
where order_number = 12;