--查询出各科成绩最好的学生信息
--自连接
--SELECT TOP 1 * FROM Score B WHERE B.ScoreName = '数学' ORDER BY B.Score DESC

SELECT A.ID,U.Name,A.ScoreName,A.Score
FROM Score A,[User]U
WHERE UID IN (SELECT TOP 1 UID
FROM Score B
WHERE B.ScoreName = A.ScoreName
ORDER BY B.Score DESC) AND A.UID=U.ID
ORDER BY A.ScoreName, A.Score DESC