create table CLASS
(
  CLASSID   VARCHAR2(10) not null,
  CLASSNAME VARCHAR2(30) not null
);

alter table CLASS
add constraint PK_CLASS primary key (CLASSID);


create table NCLASS
(
  NCLASSID   VARCHAR2(10) not null,
  NCLASSNAME VARCHAR2(30) not null,
  PARENTID   VARCHAR2(10) not null
);

alter table NCLASS
add constraint PK_NCLASS primary key (NCLASSID);

alter table NCLASS
add constraint FK foreign key (PARENTID)
references CLASS (CLASSID) on delete cascade;


insert into CLASS (CLASSID, CLASSNAME)
values ('1', '陜西省');
insert into CLASS (CLASSID, CLASSNAME)
values ('2', '新疆自治區');
insert into CLASS (CLASSID, CLASSNAME)
values ('3', '四川省');
insert into CLASS (CLASSID, CLASSNAME)
values ('4', '山東省');
commit;


insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('1', '西安', '1');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('2', '安康', '1');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('3', '銅川', '1');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('4', '烏魯木齊', '2');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('5', '庫爾勒', '2');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('6', '昌吉', '2');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('7', '伊寧', '2');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('8', '成都', '3');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('9', '綿陽', '3');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('10', '青島', '4');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('11', '濰坊', '4');
insert into NCLASS (NCLASSID, NCLASSNAME, PARENTID)
values ('12', '濟南', '4');
commit;