50個SQL語句(MySQL版) 問題二十五

--------------------------表結構--------------------------

student(StuId,StuName,StuAge,StuSex) 學生表

teacher(TId,Tname) 教師表

course(CId,Cname,C_TId) 課程表

sc(SId,S_CId,Score) 成績表

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問題二十五：查詢各科成績前三名的記錄(不考慮成績併列情況)

SELECT * FROM
(SELECT s1.S_CId,s1.Score,COUNT(DISTINCT s2.Score) Rank
FROM sc AS s1
INNER JOIN sc AS s2
ON s1.S_CId=s2.S_CId AND s1.Score<s2.Score
GROUP BY s1.S_CId,s1.Score) score
WHERE score.Rank>=1 AND score.Rank<=3 
GROUP BY score.S_CId,score.Rank;

答案僅供參考，不一定完全正確，若發現錯誤或有更好的，歡迎評論，互相交流，一起成長！！！