SQL Server PIVOT perhaps?

Question

SELECT Name1, Name2, Value FROM mytable gives me the following result set:

Name1 Name2 Value
A     P1     1
A     P2     1
A     P3     2
B     P1            


        

Answer 1

I don't have SQL Server running here at work so this may not by completely syntatically correct but one approach would be cross tabulation

SELECT name2
     , SUM(CASE WHEN name1 = 'A' THEN value END) AS A
     , SUM(CASE WHEN name1 = 'B' THEN value END) AS B
FROM table
GROUP BY name2

For variable number of columns you could use dynamic SQL:

DECLARE @sql varchar(max)
SELECT @sql = COALESCE(@sql+',','') + 'SUM(CASE WHEN nane1 = '''+name1+''' THEN value END) AS ['+name1']' FROM table

SET @sql = 'SELECT name2, '+@sql+' FROM table GROUP BY name2'

EXEC(@sql)