Question

I have a Linq statement that has to check which Client is connected to which user

     public List<Client_Dto> GetClientByBehandelaar(string loggedInUserId)
    {
        try
        {
            int userID = Convert.ToInt32(loggedInUserId);
            nestorDBDataContext db = new nestorDBDataContext();
            var result =
                (from relaties in db.tbl_Relaties
                 where relaties.ID_Persoon == userID
                 select new Client_Dto()
                 {
                     ID = relaties.NestorNrCliënt
                 }).ToList();
            List<Client_Dto> clienten = result;
            return clienten;
        }
        catch (Exception e)
        {
            throw new ArgumentException("GetClientByBehandelaar Failed " + e);
        }
    }

but it only selects one even when there are 87 more in the DB with the same userID. I’ve been staring myself to death on this one .. Can someone help

Answer 1

I tried it here and your code works:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{

    class Relatie
    {
        public Int32 ID_Persoon { get; set; }
        public Int32 NestorNrCliënt { get; set; }

        public Relatie(int ID_Persoon, int NestorNrCliënt)
        {
            this.ID_Persoon = ID_Persoon;
            this.NestorNrCliënt = NestorNrCliënt;
        }
    }

    class nestorDBDataContext
    {
        public List<Relatie> tbl_Relaties = new List<Relatie> {
            new Relatie(15, 27),
            new Relatie(15, 28),
            new Relatie(15, 29),
            new Relatie(15, 30),
            new Relatie(14, 30),
            new Relatie(14, 30),
            new Relatie(14, 30),
        };
    }

    class Program
    {
        public struct Client_Dto{
            public Int32 ID;
        }

        public static List<Client_Dto> GetClientByBehandelaar(string loggedInUserId)
        {
            try
            {
                int userID = Convert.ToInt32(loggedInUserId);
                nestorDBDataContext db = new nestorDBDataContext();
                var result =
                    (from relaties in db.tbl_Relaties
                     where relaties.ID_Persoon == userID
                     select new Client_Dto()
                     {
                         ID = relaties.NestorNrCliënt
                     }).ToList();
                List<Client_Dto> clienten = result;
                return clienten;
            }
            catch (Exception e)
            {
                throw new ArgumentException("GetClientByBehandelaar Failed " + e);
            }
        }

        static void Main(string[] args)
        {
            Console.WriteLine(GetClientByBehandelaar("15").Count());
            Console.ReadKey();
        }

    }
}

Maybe you need to look at this boolean comarison ID_Persoon == userID

Use Debug.WriteLine to output the results for you.