我有2张表分别是teaching_certification和user,我现在需要从两张表中查询出不同机构下相同学历的人数。
teaching_certification:
不能直接在最后添加user_id=6或其它数字!
根据机构和学历进行分组查询,就可以查到每个机构-每种学历的人数
GROUP BY education_background
你先进teaching_certification和user组合起来,然后按照机构进行分组统计不同学历的数量
执行结果是:
select m.education_background,n.institutions_name,count(m.id) from
(select id,user_id,education_background from teaching_certification ) m
join
(select id,institutions_name from user)n
on m.user_id=n.id
GROUP BY institutions_name,education_background
如果需要user_id可以采用以下SQL
select Max(m.user_id) as user_id,m.education_background,count(m.id),n.institutions_name from
(select id,user_id,education_background from teaching_certification ) m
join
(select id,institutions_name from user)n
on m.user_id=n.id
GROUP BY institutions_name,education_background
如有帮助,谢谢采纳~