sql IFNULL

SELECT IFNULL(a, b); 如果a是null 返回b,否则返回a
SELECT IFNULL(null, "RUNOOB");
IFNULL(null, “RUNOOB”)
RUNOOB
SELECT IFNULL("Hello", "RUNOOB");
IFNULL(null, “RUNOOB”)
Hello
posted @ 2022-08-19 22:50  luoganttcc  阅读(6)  评论(0)    收藏  举报