mysql查询文章表各类别前几的文章的sql语句

 SELECT 
        a1.* 
      FROM
        Article a1 
      WHERE 
        (SELECT 
          COUNT(1) 
        FROM
          Article a2 
        WHERE a2.MpName = a1.MpName 
          AND a2.ID > a1.ID) < 3 
      ORDER BY a1.MpName,
        a1.ID DESC