去 账号、昵称重复，并取最新一次绑定记录

代码如下：

select t1.* from (SELECT ut.TransactionAccount,u.NickName,
p.ProfessorName '绑定老师',
ub.UpdateTime AS '变动时间' 
FROM dbo.UserBind ub JOIN dbo.UserTransaction ut ON ub.UserId=ut.UserId
JOIN dbo.Users u ON ub.UserId=u.UserId
JOIN dbo.Professor p ON p.Id=ub.ProfessorId
WHERE u.IsEnable=1

AND ub.UpdateTime<'2016-01-18') t1
inner join

(SELECT ut.TransactionAccount,u.NickName,

max(ub.UpdateTime) AS '变动时间' 
FROM dbo.UserBind ub JOIN dbo.UserTransaction ut ON ub.UserId=ut.UserId
JOIN dbo.Users u ON ub.UserId=u.UserId
JOIN dbo.Professor p ON p.Id=ub.ProfessorId
WHERE u.IsEnable=1 AND ub.UpdateTime<'2016-01-18'

group by ut.TransactionAccount,u.NickName) as t2
on t1.TransactionAccount=t2.TransactionAccount
and t1.变动时间=t2.变动时间

写法思路：

有时间列就取最大时间列
有自增的id就去最大id

如果是想返回一个记录集，并且有时间列的话可以这么做
select 重复列，时间列，其余列 
inner join (select 重复列,max(时间列) as 时间列 from 表 group by 重复列) AS T2
on t1.重复列=t2.重复列 and t1.时间列 =t2.时间列
from 表 AS T1

总结：

写法代码段重复很多，大家有什么好的方法呢？？？