SQLD 기출문제 예상문제 184번

다음 문제를 풀어보세요.

다음 중 부서별 급여 Top 3를 구하는 SQL로 가장 적절한 것을 고르시오.

다음은 EMP 테이블의 구조입니다.
CREATE TABLE EMP (
    EMPNO NUMBER(4) PRIMARY KEY,
    ENAME VARCHAR2(10),
    JOB VARCHAR2(9),
    MGR NUMBER(4),
    HIREDATE DATE,
    SAL NUMBER(7,2),
    COMM NUMBER(7,2),
    DEPTNO NUMBER(2)
);

SELECT DEPTNO, ENAME, SAL
FROM EMP e1
WHERE 3 > (SELECT COUNT(DISTINCT SAL)
             FROM EMP e2
             WHERE e1.DEPTNO = e2.DEPTNO
             AND e2.SAL > e1.SAL);

SELECT DEPTNO, ENAME, SAL
FROM EMP e1
WHERE 3 < (SELECT COUNT(DISTINCT SAL)
             FROM EMP e2
             WHERE e1.DEPTNO = e2.DEPTNO
             AND e2.SAL > e1.SAL);

SELECT DEPTNO, ENAME, SAL
FROM EMP e1
WHERE 3 = (SELECT COUNT(DISTINCT SAL)
             FROM EMP e2
             WHERE e1.DEPTNO = e2.DEPTNO
             AND e2.SAL > e1.SAL);

SELECT DEPTNO, ENAME, SAL
FROM EMP e1
WHERE 3 >= (SELECT COUNT(DISTINCT SAL)
             FROM EMP e2
             WHERE e1.DEPTNO = e2.DEPTNO
             AND e2.SAL > e1.SAL);