oracle 递归
时间：2010-09-13 来源：叶振华
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
(
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
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