Create table scot1.emp (empno number constraint pk_emp primary key,
                        ename varchar2(10) 
                                  constraint mu_name not null
                                  constraint upper_ename
                                        check(ename=upper(ename)),
                        mgr number constarint fk_mgr
                                  references scot1.emp(empno),
                        hiredate default sysdate);

