oracle 遞歸查詢 CONNECT BY、START WITH、CONNECT_BY_ROOT、CONNECT_BY_ISLEAF、SYS_CONNECT_BY_PATH

轉載自：http://blog.csdn.net/feier7501/article/details/21815691

 

創建表，初始化數據;

CREATE TABLE TB_COMPANY
(
  COMPANY_ID INTEGER PRIMARY KEY,
  COMPANY VARCHAR2(256),
  UP_COMPANYID INTEGER
);

INSERT INTO TB_COMPANY VALUES (0, '總公司', NULL);
INSERT INTO TB_COMPANY VALUES (1, '北京分公司', 0);
INSERT INTO TB_COMPANY VALUES (2, '上海分公司', 0);
INSERT INTO TB_COMPANY VALUES (3, '海淀區分部', 1);
INSERT INTO TB_COMPANY VALUES (4, '東城區分部', 1);
INSERT INTO TB_COMPANY VALUES (5, '黃埔區分部', 2);
INSERT INTO TB_COMPANY VALUES (6, '靜安區分部', 2);
COMMIT;

CREATE TABLE TB_COMPANY
(
  COMPANY_ID INTEGER PRIMARY KEY,
  COMPANY VARCHAR2(256),
  UP_COMPANYID INTEGER
);

INSERT INTO TB_COMPANY VALUES (0, '總公司', NULL);
INSERT INTO TB_COMPANY VALUES (1, '北京分公司', 0);
INSERT INTO TB_COMPANY VALUES (2, '上海分公司', 0);
INSERT INTO TB_COMPANY VALUES (3, '海淀區分部', 1);
INSERT INTO TB_COMPANY VALUES (4, '東城區分部', 1);
INSERT INTO TB_COMPANY VALUES (5, '黃埔區分部', 2);
INSERT INTO TB_COMPANY VALUES (6, '靜安區分部', 2);
COMMIT;

全部數據：

遞歸查詢SQL：

SELECT (RPAD(' ', 2*(LEVEL-1), '-' ) || COMPANY) COMPANY_NAME, CONNECT_BY_ROOT COMPANY, CONNECT_BY_ISLEAF, LEVEL , SYS_CONNECT_BY_PATH(COMPANY, '/')
FROM TB_COMPANY
START WITH UP_COMPANYID IS NULL
CONNECT BY PRIOR COMPANY_ID = UP_COMPANYID;

SELECT (RPAD(' ', 2*(LEVEL-1), '-' ) || COMPANY) COMPANY_NAME, CONNECT_BY_ROOT COMPANY, CONNECT_BY_ISLEAF, LEVEL , SYS_CONNECT_BY_PATH(COMPANY, '/')
FROM TB_COMPANY
START WITH UP_COMPANYID IS NULL
CONNECT BY PRIOR COMPANY_ID = UP_COMPANYID;

結果：

說明：

1. CONNECT_BY_ROOT 返回當前節點的最頂端節點 
2. CONNECT_BY_ISLEAF 判斷是否爲葉子節點，如果這個節點下面有子節點，則不爲葉子節點 
3. LEVEL 僞列表示節點深度 
4. SYS_CONNECT_BY_PATH函數顯示詳細路徑，並用“/”分隔

遞歸查詢SQL：

SELECT * FROM TB_COMPANY START WITH COMPANY_ID = 1 CONNECT BY PRIOR COMPANY_ID = UP_COMPANYID;

SELECT * FROM TB_COMPANY START WITH COMPANY_ID = 1 CONNECT BY PRIOR COMPANY_ID = UP_COMPANYID;

結果：