I have a table like as follows:
SoftwareName Count Country Project 15 Canada Visio 12 Canada Project 10 USA Visi
in SQL 2005 or later there-SQL keyword "Pivot" that does this for you, Check out the following link:
http://msdn.microsoft.com/en-us/library/ms177410.aspx
SELECT SoftwareName,
SUM( CASE Country WHEN 'Canada' THEN [Count] ELSE 0 END ) AS Canada,
SUM( CASE Country WHEN 'USA' THEN [Count] ELSE 0 END ) AS USA,
SUM( [Count] ) AS Total
FROM [Table]
GROUP BY SoftwareName;
This is called table pivoting. In your simple case, there are just two columns; in general, there could be 200 countries or so, in which case, the pivoting becomes rather hard.
There are many resources online describing how to do it: Google for 'pivot table sql'.
OK...Here's how to do it using PIVOT:
SELECT Softwarename, Canada, USA, Canada + USA As TOTAL from SoftwareDemo
PIVOT
(
SUM([Count])
FOR Country
IN (Canada, USA)
) AS x
Softwarename Canada USA TOTAL
-------------------------------------------------- ----------- ----------- -----------
Project 15 10 25
Visio 12 5 17
(2 row(s) affected)
i think you can use this Link :
Sum of unique records - better performance than a cursor
and i think using PIVOT Function have a best performance rater SUM() function.!