Mysql存储函数返回错误的值

Question

CREATE FUNCTION cleanAmount(amount DECIMAL)
    RETURNS decimal(30,2)
    LANGUAGE SQL
    DETERMINISTIC
    NO SQL
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN
DECLARE res DECIMAL;
SET res=CAST(COALESCE(amount,0.00) AS DECIMAL(30,2));
RETURN res;
END

SELECT cleanAmount('3.456');返回3,00。它应该是3,46

Answer 1

更改存储过程中res的声明： -

CREATE FUNCTION cleanAmount(amount DECIMAL(60,30))
    RETURNS decimal(30,2)
    LANGUAGE SQL
    DETERMINISTIC
    NO SQL
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN
DECLARE res DECIMAL(30,2);
SET res=CAST(COALESCE(amount,0.00) AS DECIMAL(30,2));
RETURN res;
END

Answer 2

默认小数可能是你的数字四舍五入

DECLARE res DECIMAL（30,2）