三种完整性约束关系例子

ora-00900

1.参照完整性

SQL>  create table testc(code number,
  2                      class varchar2(10),
  3                      xueke varchar2(8),
  4                      constraint c2 foreign key(code) references tests(code));

 

2.实体完整性

SQL> create table tests(name varchar2(4),
  2                     code number,
  3                     note varchar2(8),
  4                     constraint c1 primary key(code));

 

3.用户自定义完整性

SQL> create table testz(name varchar(6) constraint z1 not null,
2                       age number constraint z2 check (age between 18 and 30),
3                       *** varchar (6) constraint z3 check (*** in('男','女')),
4                       douname varchar(6) constraint z4 unique);