mysql关联外键
select a.id,a.name,
sum(case when d.status=0 then 1 else 0 end) as 待处理,
sum(case when d.status=1 then 1 else 0 end) as 带跟进,
sum(case when d.status=2 then 1 else 0 end) as 已结束,
sum(case when d.status=3 then 1 else 0 end) as 已完成
from d d,a a
where a.id = d.aid (d表的aid和a表的id对应,但d表有多条数据的aid=a.id)
group by a.id
select a.id,a.name as 处理人,c.name as 所属机构
from a a,b b,c c
where a.id = b.aid and c.id = b.cid (b表是中间表，只存放a表的id和c表的id)
就是把这两个sql语句写在一个里面