MySQL的：如何从一个数中减去一个百分比

Question

列

amount: 500 
discount_percentage: 50 

如何选择与250的量就结了？

感谢

Ĵ

Answer 1

试试这个：

SELECT amount - (amount * discount_percentage/100) 
FROM tableA; 

Answer 2

尝试使用这样的：

SELECT (amount * ((100 - discount_percentage)/100)) as result FROM tableA 

Answer 3

试试这个简单的方法。

SELECT amount * .50 
FROM TableA; 

Answer 4

创建功能

DROP FUNCTION IF EXISTS REMOVE_PERCENT; 
DELIMITER // 
CREATE FUNCTION REMOVE_PERCENT(amount decimal(10,2),perc INT(10)) 
RETURNS decimal(10,2) 
RETURN amount - (amount*perc/100); 

现在你可以用它

SELECT REMOVE_PERCENT(amount,discount_percentage) FROM tableA; 
SELECT REMOVE_PERCENT(amount,discount_percentage) FROM tableB; 
UPDATE tableA SET `result` = REMOVE_PERCENT(amount,discount_percentage) WHERE `discount_percentage` >0