How to keep column order same in dynamic pivot - sql-server

Question

I have below mentioned table :
drn RecNum Name Value
----------------------------------------------
1 1 ad1_pk 1
2 1 ad1_address1 P.O. Box 5036
3 1 ad1_address2 NULL
4 1 ad1_address3 NULL
5 1 ad1_ctyfk 56
6 1 ad1_postalcode 80155-5036
7 1 ad1_active Y
8 1 ad1_irstat A
9 1 ad1_irdata NULL
10 1 ad1_at1fk 1
1 2 ad1_pk 2
2 2 ad1_address1 1871 S. Broadway
3 2 ad1_address2 NULL
4 2 ad1_address3 NULL
5 2 ad1_ctyfk 1
6 2 ad1_postalcode 80210
7 2 ad1_active Y
8 2 ad1_irstat A
9 2 ad1_irdata NULL
10 2 ad1_at1fk 1
I am creating the pivot using the below mentioned query:
declare #var nvarchar(max)
declare #sql nvarchar(max)
set #var = stuff((select distinct ',' + name from temp
for xml path('')),1,1,'') -- **this is giving distinct column list but the order of columns get changed..**
set #sql = 'select * from temp
pivot(max(value) for name in (' + #var + ')) as pvt'
exec sp_executesql #sql
Is there a way to keep the order of the columns unchanged? I want the order of columns listed in #var to be same as in the table.

Answer 1

Add a GROUP BY and an ORDER BY clause (to replace the DISTINCT) where you build your column list as follows:
set #var = stuff((select ',' + min(name) from temp GROUP BY drn ORDER BY drn
for xml path('')),1,1,'')
And don't forget the the necessary aggregation (I've used MIN()). Thanks #Ionic.

Answer 2

This is because you're using a DISTINCT in your SELECT query. If you look at the execution plan, you can see DISTINCT SORT operation. This sorts your result based on the DISTINCT columns you specify, in this case it's Name:
To retain the order, you can try this:
set #var = stuff((
select ',' + name
from(
select
name,
drn,
rn = row_number() over(partition by name order by drn)
from temp
)t
where rn = 1
order by drn
for xml path('')),
1,1,'')