Reputation: 19
I have thousands of companies listed but for illustration; I cited 2 companies. I need to produce the column TotalSales in which values are the sum of sales per company , a year prior to its corresponding actual year & quarter.
Company Sales Quarter Year TotalSales QtrYr_Included
ABC Inc. 10,000 1 2010 null Q12009 - Q42009
ABC Inc. 50,000 2 2010 10,000 Q22009 - Q12010
ABC Inc. 35,000 3 2010 60,000 Q32009 - Q22010
ABC Inc. 15,000 4 2010 95,000 Q42009 - Q32010
ABC Inc. 5,000 1 2011 110,000 Q12010 - Q42010
ABC Inc. 10,000 2 2011 105,000 Q22010 - Q12011
SoKor Group 50,000 1 2009 null Q12008 - Q42008
SoKor Group 10,000 2 2009 50,000 Q22008 - Q12009
SoKor Group 10,000 3 2009 60,000 Q32008 - Q22009
SoKor Group 5,000 4 2009 70,000 Q42008 - Q32009
SoKor Group 15,000 1 2010 . Q12009 - Q42009
SoKor Group 20,000 3 2010 . Q22009 - Q12010
Thank you so much.
Upvotes: 2
Views: 94
Reputation: 49270
@Prdp's solution is valid. However, it would show incorrect results when there are quarters missing for a given company as it will consider whatever row was available before the missing row. A way to avoid such situation is using derived tables to generate all combinations of year,quarter and company. Left joining the original table on to this result would generate 0 sales for the missing quarters. Then use the sum
window function to get the sum of sales for the last 4 quarters for each row.
SELECT *
FROM
(SELECT C.COMPANY,
Y.[YEAR],
Q.[QUARTER],
T.SALES,
SUM(COALESCE(T.SALES,0)) OVER(PARTITION BY C.COMPANY
ORDER BY Y.[YEAR], Q.[QUARTER]
ROWS BETWEEN 4 PRECEDING AND 1 PRECEDING) AS PREV_4QTRS_TOTAL
FROM
(SELECT 2008 AS [YEAR]
UNION ALL SELECT 2009
UNION ALL SELECT 2010
UNION ALL SELECT 2011
UNION ALL SELECT 2012
UNION ALL SELECT 2013) Y --Add more years as required or generate them using a recursive cte or a tally table
CROSS JOIN
(SELECT 1 AS [QUARTER]
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4) Q
CROSS JOIN
(SELECT DISTINCT COMPANY
FROM T) C
LEFT JOIN T ON Y.[YEAR]=T.[YEAR]
AND Q.[QUARTER]=T.[QUARTER]
AND C.COMPANY=T.COMPANY
) X
WHERE SALES IS NOT NULL --to filter the result to include only rows from the original table
ORDER BY 1,2,3
Upvotes: 0
Reputation: 93754
Here is one way to do it using Sum Over
window aggregate
SELECT *,
Sum(sales)
OVER(
partition BY Company
ORDER BY [Year], [Quarter] ROWS BETWEEN 4 PRECEDING AND 1 PRECEDING)
FROM Yourtable
for Older versions
;WITH cte
AS (SELECT Row_number()OVER(partition BY Company ORDER BY [Year], [Quarter]) rn,*
FROM Yourtable a)
SELECT *
FROM cte a
CROSS apply (SELECT Sum (sales) Total_sales
FROM (SELECT TOP 4 sales
FROM cte b
WHERE a.Company = b.Company
AND b.rn < a.rn
ORDER BY [Year] DESC,
[Quarter] DESC)a) cs
Upvotes: 3