SQLD CBT 기출문제 예상문제 859번

다음 문제를 풀어보세요.

다음 보기 중 아래 'SQL A'와 동일한 결과를 반환하지 않는 SQL을 고르시오. (단, ORDERS 테이블의 CUST_ID 컬럼에는 NULL 값이 존재할 수 있다고 가정한다.)

[SQL A]
SELECT CUST_ID FROM CUSTOMERS
MINUS
SELECT CUST_ID FROM ORDERS;

SELECT DISTINCT CUST_ID FROM CUSTOMERS C
WHERE NOT EXISTS (
    SELECT 1 FROM ORDERS O WHERE O.CUST_ID = C.CUST_ID
);

SELECT DISTINCT C.CUST_ID FROM CUSTOMERS C
LEFT OUTER JOIN ORDERS O ON C.CUST_ID = O.CUST_ID
WHERE O.CUST_ID IS NULL;

SELECT DISTINCT CUST_ID FROM CUSTOMERS
WHERE CUST_ID NOT IN (
    SELECT CUST_ID FROM ORDERS
);

SELECT DISTINCT CUST_ID FROM CUSTOMERS
WHERE CUST_ID NOT IN (
    SELECT CUST_ID FROM ORDERS WHERE CUST_ID IS NOT NULL
);