SQLD CBT 기출문제 예상문제 920번

다음 문제를 풀어보세요.

다음 중 아래 PIVOT 쿼리와 실행 결과가 완전히 동일하도록 작성된 SQL을 고르시오.

[SQL]
SELECT * 
FROM ( SELECT DEPT_CD, JOB_CD, SAL FROM EMP )
PIVOT ( SUM(SAL) FOR DEPT_CD IN ('10' AS C1, '20' AS C2) );

SELECT JOB
     , SUM(CASE WHEN DEPT_CD = '10' THEN SAL END)  C1
     , SUM(CASE WHEN DEPT_CD = '20' THEN SAL END)  C2
FROM   EMP
GROUP  BY JOB;

SELECT DEPT_CD
     , SUM(CASE WHEN JOB_CD = '10' THEN SAL END)  C1
     , SUM(CASE WHEN JOB_CD = '20' THEN SAL END)  C2
FROM   EMP       
GROUP  BY DEPT_CD;

SELECT JOB
     , SUM(DECODE(DEPT_CD, '10', SAL))  C1
     , SUM(DECODE(DEPT_CD, '20', SAL))  C2
FROM   EMP
GROUP  BY ROLLUP(JOB);

SELECT DEPT_CD
     , SUM(DECODE(JOB_CD,'10', SAL))  C1
     , SUM(DECODE(JOB_CD,'20', SAL))  C2
FROM   EMP       
GROUP  BY ROLLUP(DEPT_CD);