sql 有记录返回1，无记录返回0

时间 2020-12-25 标签 sql code blog class im img co 数字 ps

方案一sql

只返回数字code

SELECT DISTINCT IF(EXISTS(SELECT 1 FROM tb WHERE id=1), 1, 0) AS res FROM tb;

做为另外一条sql赋值blog

SELECT
tb2.*，
IF(EXISTS(SELECT 1 FROM tb WHERE id=1), 1, 0) AS res
FROM tb2;

方案二class

SELECT IF(COUNT(*), 1, 0) AS res FROM tb WHERE id = 1

--做为另外一条sql赋值
SELECT
tb2.*,
(SELECT IF(COUNT(*), 1, 0) FROM tb WHERE id = 1) AS res
FROM
tb2;

OK.im