关于SQL SERVER中的CTE中的CTE应用，其实，ORACLE的CTE语法完全一样，看示例：
一、创建示例数据表如下：
1 declare 2 tableExistedCount number; 3 begin 4 select count(1) into tableExistedCount from user_tables where TABLE_NAME ='DemoOrganization'; 5 if tableExistedCount =1 then 6 execute immediate ' drop table DemoOrganization cascade constraints'; 7 end if; 8 end; 9 10 /*==============================================================*/ 11 /* Table: DemoOrganization */ 12 /*==============================================================*/ 13 create table DemoOrganization 14 ( 15 OrgID NUMBER(20,0) not null, 16 OrgCode VARCHAR2(100), 17 OrgName NVARCHAR2(100), 18 OrgPath VARCHAR2(500), 19 ParentID INTEGER, 20 OLevel INTEGER default 0, 21 OrderID NUMBER(10,0), 22 CurState INTEGER default 0, 23 AddUser VARCHAR2(50), 24 AddTime DATE, 25 constraint PK_DEMOORGANIZATION primary key (OrgID) 26 ); 27 28 comment on table DemoOrganization is 29 '演示组织机构'; 30 31 comment on column DemoOrganization.OrgID is 32 '机构ID'; 33 34 comment on column DemoOrganization.OrgCode is 35 '机构编码'; 36 37 comment on column DemoOrganization.OrgName is 38 '机构名称'; 39 40 comment on column DemoOrganization.OrgPath is 41 '机构路径'; 42 43 comment on column DemoOrganization.ParentID is 44 '上级ID'; 45 46 comment on column DemoOrganization.OLevel is 47 '级别'; 48 49 comment on column DemoOrganization.OrderID is 50 '排序'; 51 52 comment on column DemoOrganization.CurState is 53 '当前状态'; 54 55 comment on column DemoOrganization.AddUser is 56 '创建人'; 57 58 comment on column DemoOrganization.AddTime is 59 '创建时间';
并插入测试数据：
1 drop sequence SEQ_DEMOORGANIZATION; 2 -- Create sequence 3 create sequence SEQ_DEMOORGANIZATION 4 minvalue 1 5 maxvalue 999999999999999 6 start with 1 7 increment by 1 8 cache 201; 9 10 create or replace trigger TRI_SEQ_DEMOORGANIZATION 11 before insert on DEMOORGANIZATION 12 13 for each row 14 begin 15 select SEQ_DEMOORGANIZATION.NEXTVAL into:new.ORGID from dual; 16 end; 17 18 truncate table DEMOORGANIZATION; 19 20 INSERT INTO DEMOORGANIZATION(ORGNAME,OLEVEL,ORGPATH,PARENTID ,ADDTIME ,ADDUSER, ORDERID ,CURSTATE) 21 select '组织机构1',1,'0',0,sysdate,'testUser',13,0 from dual union all 22 select '组织机构2',1,'0',0,sysdate,'testUser',12,0 from dual union all 23 select '组织机构3',1,'0',0,sysdate,'testUser' ,10,0 from dual union all 24 select '组织机构4',2,'1',1,sysdate,'testUser' ,19,0 from dual union all 25 select '组织机构5',2,'2',2,sysdate,'testUser' ,17,0 from dual union all 26 select '组织机构6',3,'1/4',4,sysdate,'testUser' ,16,0 from dual union all 27 select '组织机构7',3,'1/4',4,sysdate,'testUser' ,4,0 from dual union all 28 select '组织机构8',3,'2/5',5,sysdate,'testUser' ,3, 0 from dual union all 29 select '组织机构9',4,'1/4/6',6,sysdate,'testUser' ,5,0 from dual union all 30 select '组织机构10',4,'1/4/6',6,sysdate,'testUser' ,63,0 from dual union all 31 select '组织机构11',4,'1/4/6',6,sysdate,'testUser' ,83,0 from dual union all 32 select '组织机构12',4,'2/5/8',8,sysdate,'testUser' ,3,0 from dual union all 33 select '组织机构13',4,'2/5/8',8,sysdate,'testUser', 1,0 from dual; 34 35 select * from DEMOORGANIZATION;
二、示例：
1、--查询ORGID为2的机构包含所有子机构，且级别不大于2
WITH SimpleRecursive(ORGNAME, ORGID, ORGPATH,PARENTID,OLEVEL) AS (SELECT ORGNAME, ORGID, ORGPATH,PARENTID,0 FROM DEMOORGANIZATION WHERE ORGID = 2 UNION ALL SELECT P.ORGNAME, P.ORGID, P.ORGPATH,P.PARENTID,P.OLEVEL+1 FROM DEMOORGANIZATION P INNER JOIN SimpleRecursive A ON A.ORGID = P.PARENTID ) SELECT sr.ORGNAME as ORGNAME, c.ORGNAME as PARENTIDName,sr.ORGPATH as PARENTIDCode FROM SimpleRecursive sr inner join DEMOORGANIZATION c on sr.PARENTID=c.ORGID where c.OLEVEL<=2
2、--查询ORGID为2的机构包含所有子机构，且级别不大于3
SELECT ORGNAME as ORGNAME, (Select ORGNAME from DEMOORGANIZATION s where c.PARENTID=s.ORGID) as PARENTNAME, ORGPATH as ORGPATH,OLEVELfrom DEMOORGANIZATION c where ORGPATH like'2/%' and OLEVEL<=3
3、--查找某个ORGID为12的部门对应的所有树级部门
SELECT ORGID, OLEVEL, ORGNAME, PARENTID FROM DEMOORGANIZATION D START WITH ORGID IN (SELECT ORGID FROM DEMOORGANIZATION WHERE ORGID = 12 AND ROWNUM = 1) CONNECT BY PRIOR D.PARENTID = ORGID;
4、--查找某个ORGID为12的部门对应的顶级部门
SELECT * FROM (SELECT FIRST_VALUE(ORGNAME) OVER(ORDER BY LEVEL DESC ROWS UNBOUNDED PRECEDING) AS FIRSTID FROM DEMOORGANIZATION START WITH ORGID = 12 CONNECT BY PRIOR PARENTID = ORGID) T WHERE ROWNUM = 1