Question

I am working on a aggregate report and I have got so far with the data but I am unsure how to proceed from here. I get by with SQL but my skills are limited

I have the follow in a temp table

ID   Count  Action
2   23      Installed
2   12      Uninstalled
2   36      Unchanged
3   12      Installed
3   25      Unchanged
4   35      Installed
4   25      Unchanged

I want to convert this into this format

ID  Installed   Uninstalled Unchanged
2   23          12          36
3   12          0           36
4   35          0           25

I have no idea where to go or even how to start to achieve this and cannot find anything to point me in the right direction (Im sure its there somewhere)

Any help would be appriciated

Answer 1

Try this:

SELECT
  ID, 
  MAX(CASE WHEN "Action" = 'Installed' THEN Count END) AS 'Installed',
  MAX(CASE WHEN "Action" = 'Uninstalled ' THEN Count END) AS 'Uninstalled',
  MAX(CASE WHEN "Action" = 'Unchanged' THEN Count END) AS 'Unchanged'
FROM Table
GROUP BY ID;

Or using the SQL Server PIVOT table operator like so:

SELECT *
FROM 
(
   SELECT * FROM table
)t
PIVOT
(
   MAX("Count") FOR "Action" IN([Installed], [Uninstalled], [Unchanged])
) p

SQL Fiddle Demo for both

However, for unknown number of Actions, you will have to select them dynamically like so:

DECLARE @cols AS NVARCHAR(MAX);
DECLARE @query AS NVARCHAR(MAX);

select @cols = STUFF((SELECT distinct ',' + QUOTENAME(Action) 
                    from Table1
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'');

SET @query = 'SELECT ID,  ' + @cols + ' from 
             (
                SELECT * FROM Table1
             ) x
             PIVOT 
             (
                MAX(count)
                FOR action IN (' + @cols + ')
             ) p ';

EXECUTE(@query);

SQL Fiddle Demo(Dynamic Version)