Difference of two date time in sql server

Question

Is there a method to use SQL Server to calculate the difference between two datetimes?

For example, my dates are

1. 2010-01-22 15:29:55.090
2. 2010-01-22 15:30:09.153

So, the result should be 14.063 seconds. Can someone please help me get this output?

Answer 1

Just a note of caution with DateDiff: if you are trying to get a specific timespan, difficulties may arise because it counts the number of times you exceed the boundary you define as your units. e.g.

select datediff (m, '20100131', '20100201')

Returns a result of 1 since it crossed the barrier from January to February; hence, datediff would return a value of 1 even though the span is 2 days because it crossed one date boundary.

select datediff(mi, '2010-01-22 15:29:55.090' , '2010-01-22 15:30:09.153')

Gives a value of 1, indicating that it once crossed the minute barrier. Despite being approximately 14 seconds long, this value would be reported as one minute if the units were minutes.

I hope this helps you.