March 13, 2009 at 2:28 pm
Is there a performance difference between these 2 calculations?
IF DATEDIFF(SECOND,@StartDate,@EndDate) <0
BEGIN...
versus
IF @StartDate >= @EndDate
BEGIN...
Both variables are datetime.
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March 13, 2009 at 2:40 pm
I'd say minimal difference, but I'd personally use the second option.
March 13, 2009 at 3:14 pm
I agree with Lynn - I prefer the second method just because it is clearer what you are doing.
Jeffrey Williams
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March 13, 2009 at 10:34 pm
Marios Philippopoulos (3/13/2009)
Is there a performance difference between these 2 calculations?
IF DATEDIFF(SECOND,@StartDate,@EndDate) <0BEGIN...
versus
IF @StartDate >= @EndDateBEGIN...
Both variables are datetime.
They are not logically equivalent tests. Notice the different results in the code below. There are other problems with using DATEDIFF for this; if the time difference it too large, you will will get an overflow. The version with DATEDIFF goes to a lot of work to produce incorrect results.
declare @StartDate datetime,@EndDate datetime
select @StartDate = '20090314 00:00:00.003', @EndDate = '20090314 00:00:00.000'
IF DATEDIFF(SECOND,@StartDate,@EndDate) <0
begin print 'true 1' end else begin print 'false 1' end
IF @StartDate >= @EndDate
begin print 'true 2' end else begin print 'false 2' end
Results:
false 1
true 2
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