Oracle Start with...Connect By子句递归查询

Start with...Connect By子句递归查询一般用于一个表维护树形结构的应用。

创建示例表：

CREATE TABLE TBL_TEST 
( 
  ID    NUMBER, 
  NAME  VARCHAR2(100 BYTE), 
  PID   NUMBER                                  DEFAULT 0 
);

插入测试数据：

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');

从Root往树末梢递归

select * from TBL_TEST

start with id=1

connect by prior id = pid

从末梢往树ROOT递归

select * from TBL_TEST

start with id=5

connect by prior pid = id