CREATE TABLE DISTRICT
(
  ID         NUMBER(10)                  NOT NULL,PARENT_ID  NUMBER(10),NAME       VARCHAR2(255 BYTE)          NOT NULL
);

ALTER TABLE DISTRICT ADD (
  CONSTRAINT DISTRICT_PK
 PRIMARY KEY
 (ID));

ALTER TABLE DISTRICT ADD (
  CONSTRAINT DISTRICT_R01 
 FOREIGN KEY (PARENT_ID) 
 REFERENCES DISTRICT (ID));
 
 
 insert into DISTRICT (id,parent_id,name)
values (1,null,‘四川省‘);
insert into DISTRICT (id,name)
values (2,1,‘巴中市‘);
insert into DISTRICT (id,name)
values (3,‘达州市‘);
insert into DISTRICT (id,name)
values (4,2,‘巴州区‘);
insert into DISTRICT (id,name)
values (5,‘通江县‘);
insert into DISTRICT (id,name)
values (6,‘平昌县‘);
insert into DISTRICT (id,name)
values (7,3,‘通川区‘);
insert into DISTRICT (id,name)
values (8,‘宣汉县‘);
insert into DISTRICT (id,name)
values (9,8,‘塔河乡‘);
insert into DISTRICT (id,name)
values (10,‘三河乡‘);
insert into DISTRICT (id,name)
values (11,‘胡家镇‘);
insert into DISTRICT (id,name)
values (12,‘南坝镇‘);
insert into DISTRICT (id,name)
values (13,6,‘大寨乡‘);
insert into DISTRICT (id,name)
values (14,‘响滩镇‘);
insert into DISTRICT (id,name)
values (15,‘龙岗镇‘);
insert into DISTRICT (id,name)
values (16,‘白衣镇‘);
commit;

SELECT *
FROM district
START WITH NAME =‘巴中市‘
CONNECT BY PRIOR ID=parent_id

SELECT *
FROM district
START WITH NAME =‘平昌县‘
CONNECT BY PRIOR parent_id=ID

SELECT d.*,connect_by_root(d.id),connect_by_root(NAME)
FROM district d
WHERE NAME=‘平昌县‘
START WITH d.parent_id=1    --d.parent_id is null 结果为四川省
CONNECT BY PRIOR d.ID=d.parent_id

SELECT ID,NAME,sys_connect_by_path(NAME,‘->‘) namepath,LEVEL
FROM district 
START WITH NAME=‘巴中市‘
CONNECT BY PRIOR ID=parent_id

WITH t (ID,NAME) --要有列名
AS(
SELECT ID,NAME FROM district WHERE NAME=‘巴中市‘
UNION ALL
SELECT d.ID,d.parent_id,d.NAME FROM t,district d --要指定表和列表，
WHERE t.id=d.parent_id
)
SELECT * FROM t;

WITH t (ID,NAME) --要有表
AS(
SELECT ID,NAME FROM district WHERE NAME=‘通江县‘
UNION ALL
SELECT d.ID,district d --要指定表和列表，
WHERE t.parent_id=d.id
)
SELECT * FROM t;