问题
Possible Duplicate:
SQL Server datetime2 vs datetime
What is the difference between DbType.DateTime and DbType.DateTime2 in .NET?
If I am using DbType.Date and I want to change to a DateTime type should I use DateTime or DateTime2?
回答1:
DbType.DateTime and DbType.DateTime2 both map to the .NET type System.DateTime. If you need to have additional precision and dates that go back before 1753, then use DateTime2; otherwise DateTime will suffice.
This MSDN link explains it pretty well.
Hope this helps!
回答2:
DbType.DateTime2 and DbType.DateTime mirror exactly the types found in SQL Server as stated by this post.
When I do SQL Server work, I don't usually need that extra resolution, nor do I go back to 1753, so in .NET I tend to use System.DateTime for this and not either one. If you need to go way back in time or need mad precision, use DbType.DateTime2 paired with a SQL Server type of DateTime2.
So in short, if you're programming using Access, you probably shouldn't be using either one.
来源：https://stackoverflow.com/questions/3498817/difference-between-datetime-and-datetime2