SQLD 함수 기출문제 #641

다음 SQL의 결과는? (Oracle)

SQL
WITH test AS (
  SELECT 'A' col1, TO_DATE('2023-02-28', 'YYYY-MM-DD') dt FROM DUAL
  UNION ALL
  SELECT 'B', TO_DATE('2023-02-29', 'YYYY-MM-DD') FROM DUAL
)
SELECT col1, 
       CASE WHEN dt IS NULL THEN 'INVALID' 
            ELSE TO_CHAR(ADD_MONTHS(dt, 12), 'YYYY-MM-DD') 
       END result
FROM test;

① A: 2024-02-28, B: 2024-02-29 ② A: 2024-02-28, B: INVALID ③ A: 2024-03-01, B: INVALID ④ 오류 발생