mysql - 嵌套sql怎么办？

Question

我的输入只是用户ID。如何组合三个表来获取区域名称。我很确定我的语法是正确的

TABLE NAME: userinfo userid PRIMARY KEY

TABLE NAME: userinfo_attarea employee_id FOREIGN KEY userid REFERENCE userinfo area_id FOREIGN KEY area_id REFERENCE personnel area

TABLE NAME: personnel area area_id PRIMARY KEY areaname

我尝试过但失败了，

SELECT areaname FROM userinfo a
INNER JOIN (SELECT *FROM userinfo_attarea b
INNER JOIN SELECT *FROM personnel_area c
ON b.areaid = c.areaid
) b ON a.userid = b.employee_id;

Answer 1

我认为这个查询会对您有所帮助

select areaname from personel_area pa inner join
userinfo_attarea ut on pa.area_id=ut.area_id
inner join userinfo ui on ut.employee_id=ui.userid