Group By Concurrent Years

Hi and thank you in advance to whomever takes the time to read this entry. I will be as detailed as possible, so I apologize for the length. The information here relates to the automotive industry, but I don't believe that is a very important detail

The overall purpose of this query is to create a compressed set of the data that exists in the database. The de-normalized information is structured like the following (including made-up data):




Code Block
PartNumber Make Model Year
-------------------------------------------------------
835100 ACURA INTEGRA 2004
835100 ACURA INTEGRA 2003
835100 ACURA INTEGRA 2001
835100 ACURA INTEGRA 2000
835100 FORD FOCUS 2002





There is any number of part numbers, makes, etc in this mix. The query that I currently use is utilizing MAX and MIN functions to determine year range, but as in the sample above, this does not take into account the fact that there could be a year skipped in the middle. I could probably use a cursor to do this, but would really like to stick to set logic if at all possible.


My existing query is:




Code Block
SELECT DISTINCT
cwi.PartNumber
,RTRIM(lv.Make) AS Make
,MIN(lv.Year) AS StartYear
,MAX(lv.Year) AS EndYear
FROM
CWIParts AS cwi
INNER JOIN PartTypes AS pt
ON cwi.PartTypeID = pt.PartTypeID
INNER JOIN PartDetail AS pd
ON cwi.PartNumber = pd.PartNumber
INNER JOIN Status AS s
ON pd.StatusCode = s.StatusCode
INNER JOIN LegacyVehicle AS lv
ON cwi.LegacyVehicleID = lv.LegacyVehicleID
WHERE
cwi.PartTypeID = 10
AND s.Status = 'Active'
GROUP BY
lv.Make
ORDER BY
cwi.PartNumber ASC
,cwi.Make ASC





In hopes to end up with a result set that has 1 row for each unique part-number, make, and consecutive year range relevant to the part-number and make. I will also need to add the functionality to add other attributes (such as Model and Liters), but those are equality based and can be passed in easily.


I had done most of this programatically in vb.net, but I would much rather push this logic back to SQL Server. Thank you all for any help that you can provide on this topic.

- Jay Soares