我的SQL，如果其他條件

Question

SELECT price, sale, (IF(sale > 0) THEN ((price-sale)/price)*100 ELSE sale) AS discount FROM tbl_business_service_price 

需要解決這個問題，不想計算的百分比爲100％時的銷售價格爲0.00

Answer 1

試試這個..

SELECT price, sale, IF(sale > 0, (price-sale/price) * 100, sale) AS discount FROM tbl_business_service_price 

Answer 2

你有混合使用if和case when語法，通常看一下官方doc，就可以得到你想要的。

if溶液：

SELECT 
    price, 
    sale, 
    IF(sale > 0, ((price - sale)/price) * 100, sale) AS discount 
FROM tbl_business_service_price 

case when溶液：

SELECT 
    price, 
    sale, 
    case when sale > 0 then ((price - sale)/price) * 100 else sale end AS discount 
FROM tbl_business_service_price