Show ordered Articles per User - sql-server

Question

I have the following:
customerID | OrderID | OrderPosition | Articlenumber|
-----------+---------+---------------+--------------+
101 | 1 | 1 | 123 |
101 | 1 | 2 | 799 |
102 | 2 | 1 | 111 |
103 | 3 | 1 | 456 |
101 | 4 | 1 | 789 |
103 | 5 | 1 | 444 |
103 | 5 | 2 | 999 |
101 | 6 | 1 | 555 |
101 | 6 | 2 | 777 |
101 | 6 | 3 | 222 |
and I want the following (sum up max 4 articles (ordered by orderID (higher first) and OrderPosition (lower first)) per customerID):
customerID |articelnumber 1|articelnumber 2|articelnumber 3|articelnumber 4|
-------+-------------------+---------------+---------------+---------------+
101 |555 |777 |222 | 789 |
102 |111 |NULL |NULL |NULL |
103 |444 |999 |456 |NULL |
Tried it like this this, but this is not working correct:
select *
from
(
select customerid, OrderID , OrderPosition, Articlenumber FROM table
) src
pivot
(
avg (Articlenumber)
for OrderPosition in ([articelnumber 1], [articelnumber 2], [articelnumber 3], [articelnumber 4])
) piv

Answer 1

It took me a while to get to the same results as your expected output, but I managed to get it right eventually:
if exists (select 1 from sysobjects where name = 'TempTable')
drop table TempTable;
if exists (select 1 from sysobjects where name = 'TempTable2')
drop table TempTable2;
declare #cols nvarchar(max)
, #cols2 nvarchar(max)
, #sql nvarchar(max)
, #loop int;
create table TempTable (id int primary key identity, CustomerID int, OrderID int, OrderPosition int, ArticleNumber int)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,1,1,123)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,1,2,799)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (102,2,1,111)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (103,3,1,456)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,4,1,789)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (103,5,1,444)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (103,5,2,999)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,6,1,555)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,6,2,777)
insert into TempTable (CustomerID, OrderID, OrderPosition, ArticleNumber) values (101,6,3,222);
create table TempTable2 (CustomerID int, OrderID int, OrderPosition int, ArticleNumber int, ArticleDesc varchar(100))
select #loop = min(id) from TempTable
while #loop is not null
begin
set #sql = ' insert into TempTable2 (CustomerID, OrderID, OrderPosition, ArticleNumber, ArticleDesc)
select top 4 CustomerID, OrderID, OrderPosition, ArticleNumber, ''ArticleNumber ''+cast(rank() over (order by orderID desc, OrderPosition)as varchar)
from TempTable where CustomerID = '+cast((select CustomerID from TempTable where id = #loop) as varchar)+
'order by orderID desc, OrderPosition'
exec (#sql)
select #loop = min(id) from TempTable where id > #loop
end
select
CustomerID
, sum(isnull([ArticleNumber 1],0)) [ArticleNumber 1]
, sum(isnull([ArticleNumber 2],0)) [ArticleNumber 2]
, sum(isnull([ArticleNumber 3],0)) [ArticleNumber 3]
, sum(isnull([ArticleNumber 4],0)) [ArticleNumber 4]
from
(
select
CustomerID, OrderID, OrderPosition, ArticleDesc, ArticleNumber
from TempTable2
group by CustomerID, OrderID, OrderPosition, ArticleDesc, ArticleNumber
) d
pivot
(sum(ArticleNumber) for ArticleDesc in ([ArticleNumber 1],[ArticleNumber 2],[ArticleNumber 3],[ArticleNumber 4])
) p
group by CustomerID
My answer might not be the best as the genius guys answered above, but I still get the same results...

Answer 2

If you're after just four columns and a quick output the same as listed above, you can always just use ROW_NUMBER, a CTE, and a few joins:
;with TopFour
as
(
SELECT *,
ROW_NUMBER() OVER(PARTITION BY [customerID] ORDER BY orderID DESC, OrderPosition ASC) as [TheOrder]
FROM [table]
)
SELECT
a.[customerID],
a.[Articlenumber] as [articlenumber 1],
b.[Articlenumber] as [articlenumber 2],
c.[Articlenumber] as [articlenumber 3],
d.[Articlenumber] as [articlenumber 4]
FROM
TopFour a
LEFT JOIN
TopFour b
ON
a.customerID = b.customerID
AND
b.TheOrder = 2
LEFT JOIN
TopFour c
ON
a.customerID = c.customerID
AND
c.TheOrder = 3
LEFT JOIN
TopFour d
ON
a.customerID = d.customerID
AND
d.TheOrder = 4
WHERE
a.TheOrder = 1

Answer 3

Modified Sample Data to meet Your Requirement
IF OBJECT_ID('tempdb..#TEMP ')IS NOT NULL
DROP TABLE #TEMP
;WITH CTE(customerID , OrderID , OrderPosition , Articlenumber)
AS
(
SELECT 101, 1 , 1 , 123 UNION ALL
SELECT 101, 1 , 2 , 799 UNION ALL
SELECT 102, 2 , 1 , 111 UNION ALL
SELECT 103, 3 , 1 , 456 UNION ALL
SELECT 101, 4 , 1 , 789 UNION ALL
SELECT 103, 5 , 1 , 444 UNION ALL
SELECT 103, 5 , 2 , 999 UNION ALL
SELECT 101, 6 , 1 , 555 UNION ALL
SELECT 101, 6 , 2 , 777 UNION ALL
SELECT 101, 6 , 3 , 222
)
SELECT * , SUM(ArticleNumber)OVER(PARTITION BY customerID ORDER BY customerID ) AS SumOfArticlePerCustomer
INTO #TEMP
FROM
(
SELECT * ,
ROW_NUMBER()OVER(PARTITION BY customerID ORDER BY OrderID DESC ) RNk,
'ArticleNumber_'+CAST(ROW_NUMBER()OVER(PARTITION BY customerID ORDER BY OrderID DESC ) AS VARCHAR(10)) AS ArticleNumberData
FROM CTE
)DT
WHERE RNk <= 4
SELECT * FROM #TEMP
Dynamic Sql ,which is used to get generate the column dynamically and meet the expected result
DECLARE #Sql nvarchar(max),
#DynamicColumn nvarchar(max),
#MaxDynamicColumn nvarchar(max)
SELECT #DynamicColumn = STUFF((SELECT DISTINCT', '+QUOTENAME(ArticleNumberData )
FROM #TEMP FOR XML PATH ('')),1,1,'')
SELECT #MaxDynamicColumn = STUFF((SELECT DISTINCT', '+'MAX('+QUOTENAME(ArticleNumberData )+') AS '+QUOTENAME(ArticleNumberData )+CHAR(13)+CHAR(10)
FROM #TEMP FOR XML PATH (''),TYPE).value('text()[1]','nvarchar(max)'),1,1,N'')
SET #Sql='SELECT CustomerID,'+ #MaxDynamicColumn+',SumOfArticlePerCustomer
FROM
(
SELECT *
FROM #TEMP
)AS src
PIVOT
(
MAX(Articlenumber) FOR [ArticleNumberData] IN ('+#DynamicColumn+')
) AS Pvt
GROUP BY customerID,SumOfArticlePerCustomer
ORDER BY CustomerID'
EXEC (#Sql)
PRINT #Sql