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doc_jay

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SQL 2008 - help with date range

HI,

   I have the following query:

select s.study_datetime
from dbo.patient AS p
INNER JOIN dbo.study AS s 
on s.patient_fk = p.pk
where s.study_datetime >= DATEADD(year, datediff(year, 1, getdate()), 0)
and s.study_datetime < DATEADD(year, datediff(year, -1, getdate()), 0)
order by s.study_datetime desc

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this brings back the current year up to today's date.  

result for example - here is one row:  2014-10-07 10:02:28.000

I want to edit this query to find all of 2013 only. From 1/1/2013 - 12-31-2013.   Next I will need to do 2012 & so on, but I'm sure once I have it working for 2013, it will be easy to bring back 2012 & continue from there.   How would I edit this to bring back all of those rows?  Also, if someone could help explain how the 'DATEADD' & 'DATEDIFF' work together with in this example it would really help to shed some light on this logic for me.

thanks

EDIT:  updated code above - typo
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Avatar of Phillip Burton
Phillip Burton

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Avatar of Lee
If you use the date of the 1st January 2013 and cast it, it will use midnight on that date. For the second date, you make it less that 1st January 2014 which will include anything before the 1st January 2014
select s.study_datetime
from dbo.patient AS p
INNER JOIN dbo.study AS s 
on s.patient_fk = p.pk
where s.study_datetime >= cast('1 january 2013' as datetime)
and s.study_datetime < cast('1 january 2014' as datetime)
order by s.study_datetime desc

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Avatar of Phillip Burton
Phillip Burton

datediff(year, 1, getdate()) means get the number of years from the year 1900 plus 1 and now.

DATEADD(year, THEABOVE, 0) means add that number of years from the year 1900. It gets you to the start of the current year.
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ASKER

too easy, I was under the assumption there would need to be a combo of the two functions together.  I'm sure that could be accomplished, but this is much more simple.

thanks
If you want a more complex version, no problem :-)

where s.study_datetime >= DATEADD(year, 113, 0)
and s.study_datetime <  DATEADD(year, 114, 0)

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If you want to make your first bit easier to see, you could use:

cast(year(getdate()) as char(4)) + '0101'

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