Question

I have a table (items) which is in the following format:

ITEMNO | WEEKNO | VALUE  
A1234  |   1    |  805  
A2345  |   2    |  14.50  
A3547  |   2    |  1396.70  
A2208  |   1    |  17.65  
A4326  |   6    |  19.99

It’s a table which shows the value of sales for items in a given week.

The results or what I want to display in a table format is the item number in a row followed by columns for each week containing the values, e.g.

ITEMNO | WK1 | WK2 | WK3 | WK4 | WK5  ...etc up to 52  
A1234  | 805 | 345 | 234 | 12  | 10   ...etc up to 52  
A2345  |  23 | 12  | 456 | 34  | 99   ...etc up to 52  
A3456  | 234 | 123 | 34  | 25  | 190  ...etc up to 52  

Although I’ve 52…so I’ve only data for up to week9 but that will increase with time.

So basically what it is I’m looking to display is the week number value as a column header.

Is this possible…although I’m tempted to just grab the data and display properly through code/(asp.net) but I was wondering if there was away to display it like this in SQL?

Does anyone know or think that that this might be the best way?

Answer 1

There are two ways of doing this with static SQL and dynamic SQL:

Static Pivot:

SELECT P.ItemNo, IsNull(P.[1], 0) as Wk1, IsNull(P.[2], 0) as Wk2
    , IsNull(P.[3], 0) as Wk3, IsNull(P.[4], 0) as Wk4
    , IsNull(P.[5], 0) as Wk5, IsNull(P.[6], 0) as Wk6
    , IsNull(P.[7], 0) as Wk7, IsNull(P.[8], 0) as Wk8
    , IsNull(P.[9], 0) as Wk9
FROM
(
    SELECT ItemNo, WeekNo, [Value]
    FROM dbo.Items
) I
PIVOT
(
    SUM([Value])
    FOR WeekNo IN ([1], [2], [3], [4], [5], [6], [7], [8], [9])
) as P

Dynamic Pivot:

DECLARE
@cols AS NVARCHAR(MAX),
@y    AS INT,
@sql  AS NVARCHAR(MAX);

-- Construct the column list for the IN clause
SET @cols = STUFF(
(SELECT N',' + QUOTENAME(w) AS [text()]
FROM (SELECT DISTINCT WeekNo AS W FROM dbo.Items) AS W
ORDER BY W
FOR XML PATH('')),
1, 1, N'');


-- Construct the full T-SQL statement
-- and execute dynamically
SET @sql = N'SELECT *
            FROM (SELECT ItemNo, WeekNo, Value
                    FROM dbo.Items) AS I
            PIVOT(SUM(Value) FOR WeekNo IN(' + @cols + N')) AS P;';

EXEC sp_executesql @sql;
GO