case语句

SQL>   select ename,sal,

               case when sal <=2000 then 'UNDERPAID'

                    when sal >= 4000 then 'OVERPAID'

                    else 'OK'

       end as sal

      from emp;  2    3    4    5    6  



ENAME		  SAL SAL

---------- ---------- ---------

SMITH		  800 UNDERPAID

ALLEN		 1600 UNDERPAID

WARD		 1250 UNDERPAID

JONES		 2975 OK

MARTIN		 1250 UNDERPAID

BLAKE		 2850 OK

CLARK		 2450 OK

SCOTT		 1500 UNDERPAID

KING		 5000 OVERPAID

TURNER		 1500 UNDERPAID

ADAMS		 1100 UNDERPAID



ENAME		  SAL SAL

---------- ---------- ---------

JAMES		  950 UNDERPAID

FORD		 3000 OK

MILLER		 1300 UNDERPAID



14 rows selected.