将日期和时间字段组合到日期时间，SQL Server 2008

好的 - 我问了几个人，必须有一个简单的方法来做到这一点......

Ok - I've asked a few people and there has got to be an easy way to do this....

declare @Date date
declare @Time time 
declare @datetime datetime

select @Date = convert(Date,GetDate()) 
select @Time = convert(Time,GetDate())

select @Date, @Time, @Date + @Time (+ operator fails!)

我真的必须:1)转换为字符串，然后转换为日期时间字段?2) 使用 DateAdd 和 DatePart 先添加小时，然后添加分钟，然后添加秒.....

Do I really have to: 1) convert to a string, then convert to datetime field? 2) use DateAdd and DatePart to add hours first then minutes, then seconds.....