如何获取另一列具有最大值的行中的列值？

Question

我有一个包含三个字段user_name，page和n_loads的表格。我希望按user_name对表进行分组，为每个用户名显示最大负载数和与此（最大）负载数对应的页面。我可以在一个MySQL子句中完成吗？

Answer 1

SELECT  a.*
FROM    tableName a
        INNER JOIN
        (
            SELECT  username, MAX(n_loads) n_loads
            FROM    tableName 
            GROUP   BY username
        ) b ON  a.username = b.username AND
                a.n_loads = b.n_loads

或

SELECT  a.*
FROM    tableName a
WHERE   n_loads = 
        (SELECT MAX(b.n_loads)
        FROM    tableName b
        WHERE   a.username = b.username);

• SQLFiddle Demo (both query)