您想为此使用窗口函数，而不是
group by：
select FromUser, ToUser, Message, [Date], UserId, UserFullName, UserName, UserPhotofrom (SELECt CM.FromUser, CM.ToUser, CM.Message, CM.Date, U.UserId, U.UserFullName, U.UserName, U.UserPhoto, row_number() over (partition by CM.FromUser, CM.ToUser order by [Date] desc) as seqnum FROM ConversationMessages CM INNER JOINUsers UON U.UserName = CM.FromUser WHERe CM.ToUser = @user ) sWHERe seqnum = 1ORDER BY CM.Date DESC ;
