SQLD 기출문제 예상문제 186번

다음 문제를 풀어보세요.

다음 중 PIVOT절을 사용하여 월별 상품 판매량을 구하는 SQL로 적절하지 않은 것은?

다음 SALES 테이블을 참고하여 문제를 푸시오.
CREATE TABLE SALES (
    SALE_MONTH VARCHAR2(6),
    PRODUCT_ID VARCHAR2(10),
    SALE_QTY NUMBER
);

INSERT INTO SALES VALUES ('202301', 'P001', 10);
INSERT INTO SALES VALUES ('202301', 'P002', 5);
INSERT INTO SALES VALUES ('202302', 'P001', 12);
INSERT INTO SALES VALUES ('202302', 'P003', 8);
INSERT INTO SALES VALUES ('202303', 'P002', 7);
INSERT INTO SALES VALUES ('202303', 'P003', 15);

SELECT * FROM SALES PIVOT (SUM(SALE_QTY) FOR SALE_MONTH IN ('202301' AS JAN, '202302' AS FEB, '202303' AS MAR));

SELECT * FROM SALES PIVOT (SUM(SALE_QTY) FOR PRODUCT_ID IN ('P001' AS P001, 'P002' AS P002, 'P003' AS P003));

SELECT * FROM (SELECT SALE_MONTH, PRODUCT_ID, SALE_QTY FROM SALES) PIVOT (SUM(SALE_QTY) FOR SALE_MONTH IN ('202301' AS JAN, '202302' AS FEB, '202303' AS MAR));

SELECT PRODUCT_ID, JAN, FEB, MAR FROM SALES PIVOT (SUM(SALE_QTY) FOR SALE_MONTH IN ('202301' AS JAN, '202302' AS FEB, '202303' AS MAR));