sql server联合查询

有两个表AccountsInfo，RecordWriteScore。AccountsInfo中有字段UserID，且唯一。table2中有字段UserID，Score, 且不唯一，AccountsInfo中的UserID与RecordWriteScore中的UserID是相同索引。
我现在要统计RecordWriteScore中的相同字段UserID的Score字段和。

  SELECT  b.UserID, a.GameID,sum(b.Score) as Score
  FROM [QPAccountsDB].[dbo].[AccountsInfo] as a 
  left join [QPRecordDB].[dbo].[RecordWriteScore] as b on a.UserID=b.UserID
  group by b.UserID,a.GameID
  having SUM(b.Score)>1000000
  order by Score desc