Sql query for emp with decode

Question

How to get the required output with single query to acheive IF SAL>2500 and job='manager' then display job as 'seniormanager'.
CREATE TABLE EMP(EMPNO NUMBER(4) NOT NULL,ENAME VARCHAR2(10),JOB VARCHAR2(9),MGR NUMBER(4),HIREDATE DATE,SAL NUMBER(7, 2),COMM NUMBER(7, 2),DEPTNO NUMBER(2));
INSERT INTO EMP VALUES(7521, 'WARD', 'SALESMAN', 7698,TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30);
INSERT INTO EMP VALUES(7566, 'JONES', 'MANAGER', 7839,TO_DATE('2-APR-1981', 'DD-MON-YYYY'), 2975, NULL, 20);
INSERT INTO EMP VALUES(7698, 'BLAKE', 'MANAGER', 7839,TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30);
INSERT INTO EMP VALUES(7782, 'CLARK', 'MANAGER', 7839,TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10);
INSERT INTO EMP VALUES(7788, 'SCOTT', 'ANALYST', 7566,TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
IF SAL>2500 and job='manager' then display job as 'seniormanager'
SELECT * FROM EMP
expected output
7521     WARD     SALESMAN         7698     22-FEB-81     1250     500     30
7566     JONES     SENIORMANAGER     7839     02-APR-81     2975          20
7698     BLAKE     SENIORMANAGER     7839     01-MAY-81     2850          30
7782     CLARK     MANAGER          7839     09-JUN-81     2450          10
7788     SCOTT     ANALYST           7566     09-DEC-82     3000          20

Answer 1

Hi,
The answer to "How do I ... using DECODE?", no matter how you fill in the blank, is "Don't use DECODE; use CASE instead." If you have to ask, then it's too complicated to do with DECODE.
Here's one way using CASE:
SELECT       empno, ename
,       CASE
           WHEN  job = 'MANAGER'
           AND   sal > 2500
           THEN  'SENIORMANAGER'
           ELSE  job
       END     AS d_job
,       mgr, hiredate, sal, comm, deptno
FROM       emp
;If you really, really, really want to use DECODE:
SELECT       empno, ename
,       DECODE ( job
             , 'MANAGER'
           , DECODE ( SIGN (sal - 2500)
                    , 1
                 , 'SENIORMANAGER'
                 , job
           , job
           )     AS d_job
,       mgr, hiredate, sal, comm, deptno
FROM       emp
;Nothing is literally too difficult to do in DECODE. Anything that case be done with CASE can also be done using DECODE, often using several times the amount of code. Bit which would you rther maintain: the CASE soltuion I posted first, of this DECODE soltuion. Which do you think will have more bugs? Which so you think will be faster? If you're using Oracle 8.1 (or higher) then don't use inefficient, high-maintenance code like this. Use CASE instead.
Edited by: Frank Kulash on Dec 26, 2012 3:27 PM
Added DECODE solution