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。創建示例表：CREATE TABLE TBL_TEST( ID;NUMBER, NAME; VARCHAR2(100 BYTE), PIDNUMBER; DEFAULT 0);插入測試數據：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_TESTstart with id=1connect by prior id = pid從末梢往樹ROOT遞歸select * from TBL_TESTstart with id=5connect by prior pid = id