Question

I am relatively new to writing SQL. I have a requirement where I have to display the top 5 records as it is and consolidate the rest as 1 single record and append it as the 6th record. I know top 5 selects the top 5 records, but I am finding it difficult to put together a logic to consolidate the rest of the records and append it at the bottom of the result set.

weekof          sales    year    weekno
-------------------------------------------------------------
07/01 - 07/07   2   2012    26  
07/08 - 07/14   2   2012    27  
07/29 - 08/04   1   2012    30  
08/05 - 08/11   1   2012    31  
08/12 - 08/18   32  2012    32  
08/26 - 09/01   2   2012    34  
09/02 - 09/08   8   2012    35  
09/09 - 09/15   46  2012    36   
09/16 - 09/22   26  2012    37

---

I want this to be displayed as

weekof          sales
----------------------
09/16 - 09/22   26  
09/09 - 09/15   46  
09/02 - 09/08   8   
08/26 - 09/01   2   
08/12 - 08/18   32  
07/01 - 08/11   6

Answer 1

Except when weekof spans years, this will get the data you want and in the correct order:

;WITH x AS 
(
  SELECT weekof, sales, 
    rn = ROW_NUMBER() OVER (ORDER BY [year] DESC, weekno DESC) 
  FROM dbo.table_name
)
SELECT weekof, sales FROM x WHERE rn <= 5
UNION ALL
SELECT MIN(LEFT(weekof, 5)) + ' - ' + MAX(RIGHT(weekof, 5)), SUM(sales)
FROM x WHERE rn > 5    
ORDER BY weekof DESC;

When the rows being returned span a year, you may have to return the rn as well (and just ignore it at the presentation layer):

;WITH x AS 
(
  SELECT weekof, sales, 
    rn = ROW_NUMBER() OVER (ORDER BY [year] DESC, weekno DESC) 
  FROM dbo.table_name
)
SELECT weekof, sales, rn FROM x WHERE rn <= 5
UNION ALL
SELECT MIN(LEFT(weekof, 5)) + ' - ' + MAX(RIGHT(weekof, 5)), SUM(sales), rn = 6 
FROM x WHERE rn > 5
ORDER BY rn;