SQL Query with Dynamic Columns Using Pivot

Question

I know this topic is everywhere but I couldn\'t get it to work properly. It\'s probably something very simple.

Here is a sample of the data after a basic query:

Answer 1

Using Dynamic Sql

IF OBJECT_ID('tempdb..#TempData', 'U') IS NOT NULL 
DROP TABLE #TempData;

CREATE TABLE #TempData (
    [Site] CHAR(3) NOT NULL,
    Model VARCHAR(30) NOT NULL,
    SomeCount INT NOT NULL DEFAULT(0)
    );
INSERT #TempData (Site, Model, SomeCount) VALUES
    ('AAA', 'ProLiant DL380 G7', 1), 
    ('AAA', 'OptiPlex 790', 500), 
    ('BBB', 'OptiPlex 780', 80),
    ('CCC', 'OptiPlex 790', 23);

Declare @DynamicCol nvarchar(max),@DynamicColNull nvarchar(max)
        ,@Sql nvarchar(max)

SELECT @DynamicColNull=STUFF((SELECT DISTINCT ', '+'ISNULL('+QUOTENAME(Model),','+'''0'''+') As '+QUOTENAME(Model)
                        FROM #TempData FOR XML PATH ('')),1,2,'')

SELECT @DynamicCol=STUFF((SELECT DISTINCT ', '+QUOTENAME(Model) FROM #TempData FOR XML PATH ('')),1,2,'')

SET @Sql='SELECT [Site], '+@DynamicColNull+' From
            (   
            SELECT * from #TempData
            )
            AS Src
            PIVOT
            (
            MAX(SomeCount) FOR [Model] IN ('+@DynamicCol+')
            )AS Pvt'
PRINT @Sql
EXEC(@Sql)

Result

Site    OptiPlex 780    OptiPlex 790    ProLiant DL380 G7
AAA         0               500             1
BBB         80              0               0
CCC         0               23              0

Answer 2

Give this a shot...

IF OBJECT_ID('tempdb..#TestData', 'U') IS NOT NULL 
DROP TABLE #TestData;

CREATE TABLE #TestData (
    [Site] CHAR(3) NOT NULL,
    Model VARCHAR(30) NOT NULL,
    SomeCount INT NOT NULL DEFAULT(0)
    );
INSERT #TestData (Site, Model, SomeCount) VALUES
    ('AAA', 'ProLiant DL380 G7', 1), 
    ('AAA', 'OptiPlex 790', 500), 
    ('BBB', 'OptiPlex 780', 80),
    ('CCC', 'OptiPlex 790', 23);

--==========================================================

DECLARE 
    @PivotColumns NVARCHAR(4000),
    @sql NVARCHAR(4000),
    @DeBug BIT = 0;

SELECT 
    @PivotColumns = CONCAT(@PivotColumns, N',
    ', QUOTENAME(td.Model), N' = SUM(CASE WHEN td.Model = ', QUOTENAME(td.Model, ''''), N' THEN td.SomeCount END)') 
FROM
    #TestData td
GROUP BY
    td.Model
-- ORDER BY ??? if you want the columns in a specific ordinal position.
;

SET @sql = CONCAT(N'
SELECT 
    td.[Site]',
    @PivotColumns, N'
FROM
    #TestData td
GROUP BY
    td.[Site];');

IF @DeBug = 1
BEGIN 
    PRINT (@sql);
END;
ELSE 
BEGIN 
    EXEC sys.sp_executesql @sql;
END;

Results...

Site OptiPlex 780 OptiPlex 790 ProLiant DL380 G7
---- ------------ ------------ -----------------
AAA  NULL         500          1
BBB  80           NULL         NULL
CCC  NULL         23           NULL

Answer 3

From your query

PIVOT
(
    max(Model)
    FOR Site in ' + @cols + ')
) AS piv

you should use the column Count in MAX() function and Model in FOR...IN section. this is because your new values will be the Count and your new columns will be from the values in Model