Oracle用Start with...Connect By子句遞歸查詢

Start with...Connect By子句遞歸查詢一般用于一個表維護樹形結構的應用。

建立示例表：

CREATE TABLE TBL_TEST

(

  ID    NUMBER,

  NAME  VARCHAR2(100 BYTE),

  PID   NUMBER                                  DEFAULT 0

);

插入測試資料：

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');

從Root往樹末梢遞歸

select * from TBL_TEST

 start with id=1

 connect by prior id = pid

從末梢往樹ROOT遞歸

 start with id=5

 connect by prior pid = id