select * from t_br t where exists(select * from t_br where id= t.superior_id )
id name a superior_id
266 河北 002 1
282 长沙 001 1
503 石家庄 345 266
输出1和3的记录?
------解决方案--------------------
- SQL code
declare @table table( id int , name nvarchar(10), a varchar(10), superior_id int)insert @tableselect 266, N'河北', 002, 1 union allselect 282, N'长沙', 001, 1 union allselect 503, N'石家庄', 345, 266select * from @table t where exists(select * from @table where id= t.superior_id )--#1.第一行记录superior_id=1, [email protected]=1时, 没找到,所以第一行记录被过滤了--#2.同上--#3.第三行记录superior_id=266, [email protected]=266时, 发现存在一条这样的记录,所以被返回。/*id name a superior_id503 石家庄 345 266*/
------解决方案--------------------
沒看明白什麼意思,按你寫的語句,應只能輸出
503 石家庄 345 266
這一倏記錄吧
------解决方案--------------------
- SQL code
create table tb(id int, name nvarchar(64), a varchar(32),superior_id int)insert tb select 266,'河北','002',1 union all select 282,'长沙','001',1 union allselect 503,'石家庄','345',266 select * from tb where id in (select superior_id from tb t where exists(select 1 from tb where id= t.superior_id ))union select * from tb t where exists(select 1 from tb where id= t.superior_id )/*id name a superior_id266 河北 002 1503 石家庄 345 266*/drop table tb
------解决方案--------------------
- SQL code
select * from tab t where exists(select * from tab where id= t.superior_id )
------解决方案--------------------
select * from @table t where exists(select 1 from @table where t.id = superior_id )
union all
select * from @table t where exists(select 1 from @table where id = t.superior_id )
------解决方案--------------------
用了CTE查询,方便点:
- SQL code
create table tb(id int, name nvarchar(64), a varchar(32),superior_id int)insert tb select 266,N'河北','002',1 union all select 282,N'长沙','001',1 union allselect 503,N'石家庄','345',266 union allselect 509,N'邯郸','645',503 with t(id,name,superior_id,IsChild)as(select id,name,superior_id,0 as IsChild from tbwhere superior_id=1union allselect tb.id,tb.name,tb.superior_id,t.IsChild+1 as IsChild from tbjoin t on tb.superior_id=t.idwhere tb.superior_id!=1)select * from tbwhere (id in (select superior_id from t where isChild!=0) and superior_id=1) or (id in (select id from t where isChild!=0))