Utworzenie tablicy;

create table emp4
 (  empno number(4) not null constraint emp_p3 primary key,
    ename varchar(10) check (ename = upper(ename)),
    job varchar(10),
    hiredate date default sysdate,
    nr number(2) check (nr < 99),
    ni_number varchar(12),
    sal number(7,2),
    deptno number(2) not null constraint emp_depp references dept(deptno),
    mgr number(4),
    foreign key (mgr) references emp4(empno)
);
