(Database : Basic-7) CASE

-- 어떤 계절에 태어났는지를 추가하고자 한다.
SELECT *, 
    CASE birthMonth
        WHEN 1 THEN N'겨울'
        WHEN 2 THEN N'겨울'
        WHEN 3 THEN N'봄'
        WHEN 4 THEN N'봄'
        WHEN 5 THEN N'봄'
        WHEN 6 THEN N'여름'
        WHEN 7 THEN N'여름'
        WHEN 8 THEN N'여름'
        WHEN 9 THEN N'가을'
        WHEN 10 THEN N'가을'
        WHEN 11 THEN N'가을'
        WHEN 12 THEN N'겨울'
        ELSE N'알수없음'
    END AS birthSeason
FROM players

SELECT *, 
    CASE
        WHEN birthMonth <= 2 THEN N'겨울'
        WHEN birthMonth <= 5 THEN N'봄'
        WHEN birthMonth <= 8 THEN N'여름'
        WHEN birthMonth <= 11 THEN N'가을'
        ELSE N'겨울'
    END AS birthSeason
FROM players