我希望在mysql查询中日期为0时为0

Question

SELECT (GREATEST((YEAR(NOW()) - GREATEST( M.MANUFACTURING_DATE,1900)), 0))
AS AGE,M.MANUFACTURING_DATE FROM table_name M;

上面是我的mysql查询，如果我认为MANUFACTURING_DATE = 0然后它将Age定为117，我想要一些解决方案，如果MANUFACTURING_DATE = 0，它应该使Age为0。

Answer 1

您可以使用CASE状态：

SELECT 
    CASE 
        WHEN M.MANUFACTURING_DATE=0 THEN 0
        ELSE (GREATEST((YEAR(NOW()) - GREATEST( M.MANUFACTURING_DATE,1900)), 0))
    END
    AS AGE,M.MANUFACTURING_DATE 
FROM table_name M;