passing array as parameters, stored procedures don't update result - asp.net-mvc

Question

I have an int[] and pass it as parameter to a procedure, when the method is called, no error is reported but nothing is updated in the database. There may be something wrong in my Add() since the Stored Procedure is written by another programmer. I cannot modify this stored procedure so everything must be solved in the Add().
FYI, the Add() takes an array of userIDs and a groupID as parameters, format them and run the stored procedure. The stored procedure inserts userIDs and groupID into the DB
For example:
if userIDs=[1,2,3] and groupID=4,
then I want the following data to be inserted into the DB
userID groupID
1 4
2 4
3 4
The stored procedure
USE [xyz]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[spSaveSomething]
#groupID INT,
#userIDs TEXT
AS
BEGIN
SET NOCOUNT ON;
DECLARE #handle INT
EXEC sp_xml_preparedocument #handle OUTPUT, #userIDs
DELETE FROM tbl1 WHERE i_GroupID = #groupID AND i_NetworkUserID IN (SELECT [ID] FROM OPENXML (#handle, 'ROOT/VAL', 1) WITH ([ID] INT))
INSERT INTO tbl1 (i_NetworkUserID, i_GroupID)
SELECT [ID], #groupID FROM OPENXML (#handle, 'ROOT/VAL', 1) WITH ([ID] INT)
EXEC sp_xml_removedocument #handle
END
The Add()
public void AddUsers(int[] UserIDs, int GroupID)
{
List<int> testList = new List<int>();
foreach (int id in UserIDs)
{
testList.Add(id);
}
XmlSerializer xs = new XmlSerializer(typeof(List<int>));
MemoryStream ms = new MemoryStream();
xs.Serialize(ms, testList);
string resultXML = UTF8Encoding.UTF8.GetString(ms.ToArray());
SqlParameter param1 = new SqlParameter("#userIDs", resultXML);
SqlParameter param2 = new SqlParameter("#groupID", GroupID);
context.Database.ExecuteSqlCommand("spSaveSomething #groupID, #userIDs",
param2, param1);
}

Answer 1

Convert the int[] into a string with Comma seprated and then in Stored Prodedure, us in ie
WHERE i_NetworkUserID in #UserIds

Answer 2

for me, your approach a little bit complicated.
I suggest to rewrite your procedure like
alter procedure [dbo].[spSaveSomething]
(
#groupID int,
#userIDs nvarchar(max)
)
as
begin
set nocount on
declare #tmp_Users table (ID int primary key)
insert into #tmp_Users
select T.C.value('.', 'int')
from #userIDs.nodes('List/ID') as T(C)
delete from tbl1
where
i_GroupID = #group_ID and
i_NetworkUserID in (select ID from #tmp_Users)
insert into tbl1 (i_NetworkUserID, i_GroupID)
select ID, #groupID
from #tmp_Users
-- actually it's strange - you deleting users and then inserting
-- may be you wanted to do this:
-- delete from tbl1
-- where
-- i_GroupID = #group_ID and
-- i_NetworkUserID not in (select ID from #tmp_Users)
-- insert into tbl1 (i_NetworkUserID, i_GroupID)
-- select U.ID, #groupID
-- from #tmp_Users as U
-- where
-- not exists (
-- select T.*
-- from tbl1 as T
-- where T.i_GroupID = #group_ID and T.i_NetworkUserID = U.ID
-- )
end
and your xml generation like
var userIDs = new List<int>() { 1, 2, 3 };
var userXML = new XElement("List", a.Select(x => new XElement("ID", x))).ToString();
// so userXML = "<List><ID>1</ID><ID>2</ID><ID>3</ID></List>"
hope that helps