1.MS Sql
with cte as
(
select Id,Pid,DeptName, 0 as lvl from Department
where Id = 2
union all
select d.Id,d.Pid,d.DeptName,lvl + 1 from cte c inner join Department d
on c.Id = d.Pid
)
select * from cte
2.Oracle
一、建表
CREATE TABLE USERS.TBL_TEST
(
ID NUMBER,
NAME VARCHAR2(100 BYTE),
PID NUMBER DEFAULT 0
)
INSERT INTO TBL_TEST(ID,NAME,PID) VALUES(‘1′,’10’,’0′);
INSERT INTO TBL_TEST(ID,NAME,PID) VALUES(‘2′,’11’,’1′
INSERT INTO TBL_TEST(ID,NAME,PID) VALUES(‘3′,’20’,’0′);
INSERT INTO TBL_TEST(ID,NAME,PID) VALUES(‘4′,’12’,’1′);
INSERT INTO TBL_TEST(ID,NAME,PID) VALUES(‘5′,’121′,’2’);
二、格式
Select * from …. Where [结果过滤条件语句]
Start with [and起始条件过滤语句]
Connect by prior [and中间记录过滤条件语句]
三、查找所有下级
select * from tbl_test start with id=1 connect by prior id=pid
注意:此sql能查找id=1的数据的所有下级,写sql语句时要注意,因为是从id开始查找下级,所以connect by prior 子句的条件是id=pid
四、查找所有上级
select * from tbl_test start with id=5 connect by prior pid=id
因为是从id开始查找上级,所以connect by prior 子句的条件是pid=d
sql语句查询下级下下级
原文作者:SQL
原文地址: https://blog.csdn.net/xionglangs/article/details/52371267
本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
原文地址: https://blog.csdn.net/xionglangs/article/details/52371267
本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。