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
