SQLD CBT 기출문제 예상문제 419번

다음 문제를 풀어보세요.

다음 중 아래 SQL 문과 동일한 결과를 반환하는 SQL로 가장 적절한 것을 고르시오.

SELECT CUSTOMER_ID FROM ORDERS
EXCEPT
SELECT CUSTOMER_ID FROM REFUNDS;

SELECT DISTINCT A.CUSTOMER_ID 
FROM ORDERS A 
WHERE EXISTS (SELECT 1 FROM REFUNDS B WHERE A.CUSTOMER_ID = B.CUSTOMER_ID);

SELECT DISTINCT A.CUSTOMER_ID 
FROM ORDERS A 
WHERE NOT EXISTS (SELECT 1 FROM REFUNDS B WHERE A.CUSTOMER_ID = B.CUSTOMER_ID);

SELECT A.CUSTOMER_ID 
FROM ORDERS A 
INNER JOIN REFUNDS B ON A.CUSTOMER_ID = B.CUSTOMER_ID;

SELECT CUSTOMER_ID FROM ORDERS
INTERSECT
SELECT CUSTOMER_ID FROM REFUNDS;