SQL Server Pivots: Displaying row values to column headers - sql-server

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

Answer 2

Maybe something like this:
Test data
CREATE TABLE #tbl
(
ITEMNO VARCHAR(100),
WEEKNO INT,
VALUE FLOAT
)
INSERT INTO #tbl
VALUES
('A1234',1,805),
('A2345',2,14.50),
('A3547',2,1396.70),
('A2208',1,17.65),
('A4326',6,19.99)
Week columns
DECLARE #cols VARCHAR(MAX)
;WITH Nbrs ( n ) AS (
SELECT 1 UNION ALL
SELECT 1 + n FROM Nbrs WHERE n < 52 )
SELECT #cols = COALESCE(#cols + ','+QUOTENAME('WK'+CAST(n AS VARCHAR(2))),
QUOTENAME('WK'+CAST(n AS VARCHAR(2))))
FROM
Nbrs
Just the included weeks
DECLARE #cols VARCHAR(MAX)
;WITH CTE
AS
(
SELECT
ROW_NUMBER() OVER(PARTITION BY WEEKNO ORDER BY WEEKNO) AS RowNbr,
WEEKNO
FROM
#tbl
)
SELECT #cols = COALESCE(#cols + ','+QUOTENAME('WK'+CAST(WEEKNO AS VARCHAR(2))),
QUOTENAME('WK'+CAST(WEEKNO AS VARCHAR(2))))
FROM
CTE
WHERE
CTE.RowNbr=1
Dynamic pivot
DECLARE #query NVARCHAR(4000)=
N'SELECT
*
FROM
(
SELECT
tbl.ITEMNO,
''WK''+CAST(tbl.WEEKNO AS VARCHAR(2)) AS WEEKNO,
tbl.VALUE
FROM
#tbl as tbl
) AS p
PIVOT
(
SUM(VALUE)
FOR WEEKNO IN ('+#cols+')
) AS pvt'
EXECUTE(#query)
Drop the temp table
DROP TABLE #tbl

Answer 3

Use Pivot, although quite a bit of code..
If you create report in reporting services, can use matrix..

Answer 4

Follow the below walkthrogh which explains it clearly
http://www.tsqltutorials.com/pivot.php

Answer 5

You can use PIVOT if you want to do this in sql directly.
It can be more efficient to use the SQL Server to do this as opposed to the client depending upon the size of the data and the aggregation.