Concatenate dynamically pivoted columns for a variable number of columns - sql-server

Question

I have been able to successfully pivot different field values into separate columns but what I want is to concatenate all of those separate (pivoted) columns into one column. I don't know how many pivoted columns that I end up with at runtime so I can't just use Column1 + Column2 + Column3 etc.
Here is my sql
--Create a table variable to hold my source data
declare #datatable table
(
OrderId int,
ProductId int,
ClientName varchar(50)
)
--insert some data
insert into #datatable values (1, 2, 'Joe Bloggs')
insert into #datatable values (1, 2, 'Frank Bloggs')
--Create a temp table
--that introduces a new field (called Header)
--to give me column names for my pivoted data
IF OBJECT_ID('tempdb..#PivotedClients') IS NOT NULL DROP TABLE #PivotedClients
create table #PivotedClients
(
OrderId int,
ProductId int,
ClientName varchar(50),
Header varchar(100)
)
insert into #PivotedClients
select OrderId,
ProductId,
ClientName,
'Client ' + Cast(Rank() Over (Partition by OrderId
order by ClientName) as varchar(3))
from #datatable
--Create variables to hold my column names
--and my (dynamic) sql
declare #pivotcolumns nvarchar(max),
#colsWithNoNulls nvarchar(max),
#sqlquery nvarchar(max)
set #pivotcolumns = STUFF(
(
select distinct ',' + QUOTENAME(Header)
from #PivotedClients
for XML PATH (''), TYPE
).value('.', 'nvarchar(max)')
,1,1,'')
set #colsWithNoNulls = STUFF(
(
SELECT DISTINCT ',ISNULL(' + QUOTENAME(Header) + ', '''') ' + QUOTENAME(Header)
FROM #PivotedClients
for XML PATH (''), TYPE
).value('.', 'NVARCHAR(max)')
,1,1,''
)
if OBJECT_ID('tempdb..##Clients ') is not null drop TABLE ##Clients
set #sqlquery = 'select distinct OrderId,
ProductID,
' + #colsWithNoNulls + '
into ##Clients
from
(
select OrderId,
ClientName,
ProductID,
Header
from #PivotedClients) x
pivot
(
Max(ClientName)
for Header in (' + #pivotcolumns + ')
) p'
exec sp_executesql #sqlquery
----
select *
from ##Clients
----
The record set that I currently end up with is:
OrderId ProductId Client1 Client 2
1 2 Frank Bloggs Joe Blogs
What I want is:
OrderID ProductId Clients
1 2 Frank Bloggs Joe Bloggs
I don't know how many 'pivoted' columns that I will end up with at runtime so I can't just use Client1 + Client2 etc

Answer 1

Just need to change your #colsWithNoNulls to perform the string concatenation
set #colsWithNoNulls = STUFF(
(
SELECT DISTINCT '+ '' '' + ISNULL(' + QUOTENAME(Header) + ', '''')'
FROM #PivotedClients
for XML PATH (''), TYPE
).value('.', 'NVARCHAR(max)')
, 1, 1, '') + 'AS Clients'
Also you can do a print #sqlquery before sp_executesql. this will helps you debug your dynamic query