set a variable in outer apply statement sql - sql

Question

I want to get one row in Outer apply statement for one of task Id, but SQL be angry me in outer apply statement with red line :) Any ideas ?
declare #OwnerUserIDs as Nvarchar(max)
select bt.*
,cu.NAME+' '+cu.SURNAME as OwnerUserName
,cu2.NAME+' '+cu2.SURNAME as CreatedUserName
,T.Data
from Business_Tasks(nolock) bt
left join CommmerceCoreReleaseV1..CORE_USERS(nolock) cu on cu.USERID=bt.OwnerUserID
left join CommmerceCoreReleaseV1..CORE_USERS(nolock) cu2 on cu2.USERID=bt.CreatedUserID
outer apply
(
SELECT #OwnerUserIDs = Data from ( select COALESCE(#OwnerUserIDs + ';', '') + convert(nvarchar,bto.ownerUserID) as Data from Business_TasksOwner(nolock) bto where bto.TaskID=13)
) T
where bt.IsActive=1 and bt.ID=13
Answer
Hi, I found the answer, i changed inside of outer apply statement :
select bt.*
,cu.NAME+' '+cu.SURNAME as OwnerUserName
,cu2.NAME+' '+cu2.SURNAME as CreatedUserName
,T.OwnerUserIDs
from Business_Tasks(nolock) bt
left join CommmerceCoreReleaseV1..CORE_USERS(nolock) cu on cu.USERID=bt.OwnerUserID
left join CommmerceCoreReleaseV1..CORE_USERS(nolock) cu2 on cu2.USERID=bt.CreatedUserID
outer apply
(
select STUFF((SELECT ';'+ convert(nvarchar,bto.OwnerUserID)
FROM Business_TasksOwner(nolock) bto
where bto.TaskID=bt.ID
FOR XML PATH('')), 1, 1, '') AS OwnerUserIDs
) T
where bt.IsActive=1 and bt.ID=13

Answer 1

Okay, there are a few issues with your query as it stands:
you need to add an alias name to your inner query, the one that starts "SELECT COALESCE...", i.e. put a letter, say X, after "bto.TaskId = 13)".
you can't set your variable to the results of this sub-query the way you have, if you remove the "#OwnerUserIDs = " bit then your query should compile;
I don't understand what your OUTER APPLY is trying to achieve, surely it will just return the same results for every row returned, i.e. where TaskId = 13? Maybe this should be referring to the main query in some way?
If you want to set the #OwnerUserIDs to be the concatenated results of the OwnerUserIDs then you need to use a different mechanism, either a recursive CTE or XML PATH query would work.
I would try to rewrite your query for you but I am not sure what you are trying to achieve here. I guess you want to end up with a list of User Ids in #OwnerUserIDs but I'm not sure what the rules should be...