How to calculate difference in hours (decimal) between two dates in SQL Server?

Question

I have to calculate the difference in hours (decimal type) between two dates in SQL Server 2008.

I couldn\'t find any useful technique to convert datetime to decimal

Answer 1

Declare @date1 datetime
Declare @date2 datetime

Set @date1 = '11/20/2009 11:00:00 AM'
Set @date2 = '11/20/2009 12:00:00 PM'

Select Cast(DateDiff(hh, @date1, @date2) as decimal(3,2)) as HoursApart

Result = 1.00