问题:现有如下数据表,用户表: Members(QQnumber,userid); 充值表: Payment(payid,userid,paytime,amount); 查询2012年各个月充值最多的用户的qqnumber,要求根据qqnumber进行汇总(提示:一个qqnumber可能会有多个游戏角色数据,多条充值记录;paytime为充值时间,),请写出SQL语句。创建的表如下。Members表

Payment表
查询语句如下:方法一:SELECT MAX( amount ) , t.qqnumber, t.MONTH FROM (SELECT MONTH( a.paytime ) MONTH , b.qqnumber, SUM( a.amount ) amount FROM payment a, members bWHERE a.userid = b.userid AND YEAR( a.paytime ) = '2016' GROUP BY b.qqnumber, MONTH ) AS t GROUP BY t.MONTH;方法二:SELECT MAX( amount ) , t.qqnumber, t.month FROM (SELECT MONTH( p.paytime ) AS MONTH , SUM( p.amount ) AS amount, m.qqnumber AS qqnumberFROM Members m JOIN Payment p ON m.userid = p.useridWHERE YEAR( p.paytime ) =2016 GROUP BY m.qqnumber, MONTH) AS t GROUP BY t.month;新闻热点
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