SQL分组查询最大值最小值

查询语句参考如下：
select
UserName,--
Convert(char(8),dealTm,112) as date,--日期
min(dealTm) as earliestTime ,--最大
max(dealTm) as latestTime--最小
from t2
group by Convert(char(8),dealTm,112) ,UserName

---