Question

I have a temp table variable that I need to update with something sort of like a comma delimited string.

declare @clients table (clientid int, hobbylist char(1000))
declare @hobbies table (clientid int, hobbynumber smallint)

insert into @clients values (3, '')
insert into @clients values (5, '')
insert into @clients values (12, '')

insert into @hobbies values (3, 4)
insert into @hobbies values (3, 5)
insert into @hobbies values (3, 7)
insert into @hobbies values (12, 3)
insert into @hobbies values (12, 7)

So @clients contains:

clientid     hobbylist
---------------------------
3
5
12

And @hobbies contains:

clientid     hobbylist
---------------------------
3            4
3            5
3            7
12           3
12           7

I need to update the @clients table so that it contains:

clientid     hobbylist
---------------------------
3            4;;5;;7
5
12           3;;7

The closest thing that I found was this:
How to concatenate multiple rows?
But I can’t understand how he is getting “one, two, three” looking at the what is marked as the correct answer.

I’m using SQL Server 2008 R2 64. I tried using a cursor but it was slow (and there will be tons of this type of thing in this sp).

What’s the most efficient way to do this?

Edit:

From njk’s suggestion, I tried this:

update c
set hobbylist=Stuff((
            Select  ';;' + cast(hobbynumber as char)
            From    @hobbies h
            Where   h.clientid = c.clientid
            For             XML Path('')
    ), 1, 1, '')
from @clients c

It didn’t give me an error, but the result is so wacked, I can’t find a good way to show it here.

e.g. Hobby list for client 3 looks like this:

;4                             ;;5                             ;;7                                                                                                                               

ALMOST works. Don’t know where the spaces are coming from.

Edit 2.

Duh. I’m using cast. I need to trim the thing. This solution works for me on my server. I’m going to see if I can get ClearLogic’s working, as well, so I can mark it as a correct answer.

Answer 1

Here you go

       ;WITH CTE AS 
         (SELECT DISTINCT  clientid,hobbylist= STUFF((SELECT ';'+ LTRIM(STR(hobbynumber))
          FROM @hobbies yt
           WHERE yt.clientid = sc.clientid            
         FOR XML PATH(''), TYPE).value('.','VARCHAR(max)'), 1, 1, '')
         FROM @hobbies AS sc 
         )
         UPDATE a
         SET a.hobbylist=b.hobbylist 
         FROM @clients AS a
         INNER JOIN CTE AS b
         ON a.clientid = b.clientid