Mysql：如何从数字中减去一个百分比

Question

列

amount:  500
discount_percentage: 50

如何选择以250的金额结束？

由于

Ĵ

Answer 1

试试这个：

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

Answer 2

尝试使用：

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

Answer 3

尝试这种简单的方法。

SELECT amount * .50
FROM TableA;

Answer 4

创建一个功能

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);

现在你可以使用它了

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