I have to make a query to a table of a database that is hosted in a MSSQL server.
The query is the following:
select *
from tableA
where createdOn between @startDate and @endDate
The type of variables @startDate and @endDate is datetime. If @endDate is equal to the current date and @startDate is equal to the date once month before, I thought that we could make the query either as
declare @startDate datetime
declare @endDate datetime
set @startDate = DATEADD(month,-1,GETDATE())
set @endDate = GETDATE()
select *
from tableA
where createdOn between @startDate and @endDate
or as
select *
from tableA
where createdOn between DATEADD(month,-1,GETDATE()) and GETDATE()
I thought that the first query would be faster that the second, because in the second query we call the functions in the where clause. I wrote both versions of my query and I executed them also. However, I didn't notice any significant difference in the performance.
Could someone explain me why I didn't see any change. Maybe the thought that the first query should be faster that the second was false. Please let me know, id that's the case, why is wrong.
Thanks in advance for any help.
