T-SQL - Pivot by week - sql

Question

I'm currently trying to create a T-SQL, which runs through a list of deliveries in a table, and groups them by the Customer and the Depot - so each row will be
Customer, Depot, Total Value (sum of a column called Rate)
However, the customer would like the 'total value' split into the last 9 weeks - so rather than total value, we'll have columns like this:
22/01/2012 29/01/2012 05/02/2012 12/02/2012 19/02/2012 26/02/2012 04/03/2012 11/03/2012 18/03/2012
The dates would of course change for when they run the query - it'll just be the last 9 weeks. They also want a column for the Average of all these.
I understand pivot may help me but I'm a bit stumped on how to do this. Here's my current query:
SELECT d.Name AS 'Depot, s.Name AS 'Customer', SUM(c.Rates) AS 'Total Value'
FROM Deliveries AS c INNER JOIN Account AS s ON c.Customer = s.ID
INNER JOIN Depots AS d ON c.CollectionDepot = d.Letter
GROUP BY d.Name, s.Name
Many thanks!
EDIT: Here's a screenshot of the data currently - we won't need the 'total' column on the end, just there to show you. The 'Date' column is present in the Deliveries table and is called TripDate

Answer 1

Without knowing your exact data. It hard to predict what you are getting. But I can give you a suggestion of a solution.
Table structure
CREATE TABLE Deliveries
(
Customer INT,
CollectionDepot INT,
Rates FLOAT,
TripDate DATETIME
)
CREATE TABLE Account
(
Name VARCHAR(100),
ID INT
)
CREATE TABLE Depots
(
Name VARCHAR(100),
Letter INT
)
Test data
INSERT INTO Deliveries
VALUES
(1,1,452,GETDATE()-10),
(1,1,800,GETDATE()-30),
(1,1,7895,GETDATE()-2),
(1,1,451,GETDATE()-2),
(1,1,478,GETDATE()-89),
(1,1,4512,GETDATE()-31),
(1,1,782,GETDATE()-20),
(1,1,652,GETDATE()-5),
(1,1,752,GETDATE()-452)
INSERT INTO Account
VALUES
('Customer 1',1)
INSERT INTO Depots
VALUES
('Depot 1',1)
Table that contains the ranges and the formated date
CREATE TABLE #tmp
(
StartDate DATETIME,
EndDate DATETIME,
FomatedDate VARCHAR(20)
)
Calculate the date ranges
;WITH Nbrs ( n ) AS (
SELECT 0 UNION ALL
SELECT 1+n FROM Nbrs WHERE n < 8 )
INSERT INTO #tmp
SELECT
DATEADD(WEEK,-n-1,GETDATE()),
DATEADD(WEEK,-n,GETDATE()),
convert(varchar, DATEADD(WEEK,-n,GETDATE()), 112)
FROM
Nbrs
ORDER BY
-n
The date columns for the pivot
DECLARE #cols VARCHAR(MAX)
SELECT #cols = COALESCE(#cols + ','+QUOTENAME(FomatedDate),
QUOTENAME(FomatedDate))
FROM
#tmp
Declaring some dynamic sql and executing it
DECLARE #query NVARCHAR(4000)=
N'SELECT
*
FROM
(
SELECT
Depots.Name AS Depot,
Account.Name AS Customer,
Deliveries.Rates,
tmp.FomatedDate,
AVG(Deliveries.Rates) OVER(PARTITION BY 1) AS Average,
SUM(Deliveries.Rates) OVER(PARTITION BY 1) AS Total
FROM
Deliveries
JOIN Account
ON Deliveries.Customer = Account.ID
JOIN Depots
ON Deliveries.CollectionDepot = Depots.Letter
JOIN #tmp AS tmp
ON Deliveries.TripDate BETWEEN tmp.StartDate AND tmp.EndDate
) AS p
PIVOT
(
AVG(rates)
FOR FomatedDate IN ('+#cols+')
) AS pvt'
EXECUTE(#query)
And then cleaning up after myself.
DROP TABLE Deliveries
DROP TABLE Account
DROP TABLE Depots
DROP TABLE #tmp

Answer 2

You would have to make use of the PIVOT Keyword which is available in your version of SQL Server. I have outlined how your query should look, of course some tweaking will be required since it is difficult to test without having a copy of your data.
SELECT Depots.Name AS 'Depot', Account.Name, '22/01/2012', '29/01/2012', '05/02/2012', '12/02/2012',
FROM
(SELECT Name,
FROM Deliveries
INNER JOIN Account ON Deliveries.Customer = Account.ID
INNER JOIN Depots ON Account.CollectionDepot) AS Source
PIVOT
(
SUM(Deliveries.Rates)
FOR Date IN ('22/01/2012', '29/01/2012', '05/02/2012', '12/02/2012')
) AS 'Pivot Table'
For reference you could use this as a guide:
http://msdn.microsoft.com/en-us/library/ms177410.aspx