MYSQL牛逼应用语句

accountbase ：用户信息表
accountattention：用户关注或粉丝的关联关系表
查询粉丝列表，同时显示当前用户与粉丝用户是否是相关关注状态，返回 1：代表互关，0：只是粉丝
100000009 ：代表某个用户id

查询代码如下：

	select accid, accountname,wxnickname,wxuserpic,accountpic,1 from accountbase bb where exists (
			select a.accid from  (select accid, attentaccid from accountattention  where attentaccid = 100000009 and delflag = 0 ) a  where 
				(select count(*) from (select accid, attentaccid from accountattention where accid = 100000009 and  delflag = 0 ) b where a.accid = b.attentaccid )=1 
			and a.accid = bb.accid 
	)		
	union 	
	select accid, accountname,wxnickname,wxuserpic,accountpic,0 from accountbase bb where exists (
			select a.accid from  (select accid, attentaccid from accountattention  where attentaccid = 100000009 and delflag = 0 ) a  where 
				(select count(*) from (select accid, attentaccid from accountattention where accid = 100000009 and  delflag = 0 ) b where a.accid = b.attentaccid )=0 
			and a.accid = bb.accid 		
	)		

图：

解释语句：
获取 100000009 的粉丝用户id：
select accid, attentaccid from accountattention where attentaccid = 100000009 and delflag = 0
获取100000009 的关注用户id：
select accid, attentaccid from accountattention where accid = 100000009 and delflag = 0
获取是100000009的粉丝但不是100000009的关注用户id：
select a.accid from (select accid, attentaccid from accountattention where attentaccid = 100000009 and delflag = 0 ) a
where (
select count(*) from (select accid, attentaccid from accountattention where accid = 100000009 and delflag = 0 ) b where a.accid = b.attentaccid
) =0
例如：