T-SQL - SELECT by nearest date and GROUPED BY ID

Question

From the data below I need to select the record nearest to a specified date for each Linked ID using SQL Server 2005:

ID     Date      Linked ID         


        

Answer 1

You want to look at the absolute value of the DATEDIFF function (http://msdn.microsoft.com/en-us/library/ms189794.aspx) by days.

The query can look something like this (not tested)

with absDates as 
(
   select *, abs(DATEDIFF(day, Date_Column, '2010/10/01')) as days
   from table
), mdays as
( 
   select min(days) as mdays, linkedid
   from absDates
   group by linkedid
)
select * 
from absdates
inner join mdays on absdays.linkedid = mdays.linkedid and absdays.days = mdays.mdays