Mysql案例语句在案例评估后未返回适当的消息
我从car表中选择engineStatus字段,查询如下:-Mysql案例语句在案例评估后未返回适当的消息,mysql,sql,Mysql,Sql,我从car表中选择engineStatus字段,查询如下:- select engineStatus from car LIMIT 1 car表格列的值可以为1或0。 假设engineStatus设置为1,上述查询将返回1 如果engineStatus=1,我想返回ON;如果engineStatus=0,我想返回OFF 我尝试了下面的查询,但SQL抛出了一个错误 SELECT ( case engineStatus = 1 then SET engineStatus = 'ON' else S
select engineStatus from car LIMIT 1
car表格列的值可以为1或0。
假设engineStatus设置为1,上述查询将返回1
如果engineStatus=1,我想返回ON
;如果engineStatus=0,我想返回OFF
我尝试了下面的查询,但SQL抛出了一个错误
SELECT ( case engineStatus = 1 then SET engineStatus = 'ON' else SET status = 'OFF') FROM `car` WHERE 1
Mysql说
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'then SET engineStatus = 'ON' else SET engineStatus = 'OFF') FROM `car` WHERE 1 LI' at line 1
如何在mysql中实现这一点?应该是:
SELECT ( case WHEN engineStatus = 1 then 'ON' else
'OFF' END) FROM `car`;
您在时错过了
,因此不需要在此处设置
正确的语法是:
SELECT
( CASE
WHEN engineStatus = 1 THEN 'ON'
ELSE 'OFF'
END
) AS status
FROM `car`
WHERE 1
你错过了什么时候和结束。除了不应该在这里使用“SET”外,在selectSo中,您只想返回ON而不是1,否则返回OFF?很酷,可以!几个月前,我实现了相同的解决方案,但忘记了包含WHEN子句。