Filtering Data Table inside Hub Class PREVENTS SQL Dependency to run

问题

I am using SignalR and SQL dependency to deliver real time data based on a SQL Server query with parameter related to the user connectionId.

I have a strange problem related to SQL depedency: I am sending a userid through query string to the hub.

For each hub start, I am saving the connection Id and that userId in SQL Server database and my SQL query which I am linking to SQL dependency has filter related to the connectionId.

I tried to include the filter based on that connectionId in the query itself, but SQL dependency was not updating: the data are displayed only on starting, and if I update them in the database, they are not updated in the client
If I hard code the connection id value, SQL dependency works fine
Then I tried another solution: I don't put the filter in the original query, but I filter the result using LinQ => SQL dependency does not work (same result as in 1)
Another filtration way: using DataView => same result as in 1 and 3

My hub:

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Threading.Tasks;
using MapUsers;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using System.Data.Entity;
using SignalRDbUpdates.Models;

namespace SignalRDbUpdates.Hubs
{
    [HubName("agendaHub")]
    public class AgendaHub : Hub
    {
        string Mat = "";
        Int16 nb_formation = 0;
        Int16 nb_audit=0;
        Int16 nb_action=0;
        Int16 nb_reunion=0;
        Int16 nb_equipement = 0;
        string ConnectionId = "";
        string ConId = "";
        public static List<UserConnection> ListUser { get; set; }

        public class UserConnection
        {
            public string UserId { get; set; }
            public string ConnectionId { get; set; }
        }

        public void Hello()
        {
            Clients.All.hello();
        }

        public override Task OnConnected()
        {
            //var name = Context.User.Identity.Name;

            try
            {
                ConId = Context.ConnectionId;
                string mat;
                mat = "";

                try
                {
                    mat = Context.QueryString["uid"].ToString();
                }
                catch (Exception e)
                {
                    Cldb.Insert_error(e.Message.ToString() + " " + e.InnerException.ToString(), e.StackTrace.ToString(), "onConnected, QueryString");
                }

                ListUser = new List<UserConnection>();

                var us = new UserConnection
                {
                    UserId = Context.QueryString["uid"].ToString(),
                    ConnectionId = Context.ConnectionId
                };
                ListUser.Add(us);

                Cldb.Add_connection_to_agenda_table(mat, Context.ConnectionId);

                using (var db = new UserContext())
                {
                    var user = db.Users
                        .Include(u => u.Connections)
                        .SingleOrDefault(u => u.UserName == mat);

                    if (user == null)
                    {
                        user = new User
                        {
                            UserName = mat,
                            Connections = new List<Connection>()
                        };
                        db.Users.Add(user);
                    }

                    user.Connections.Add(new Connection
                    {
                        ConnectionID = Context.ConnectionId,                        
                        UserAgent = Context.Request.Headers["User-Agent"],
                        Connected = true,
                        ConnectionTime = DateTime.Now
                    });
                    db.SaveChanges();
                }
            }
            catch (Exception e)
            {
                Cldb.Insert_error(e.Message.ToString() + " " + e.InnerException.ToString(), e.StackTrace.ToString(), "onConnected");
            }
            return base.OnConnected();
        }

        public override Task OnDisconnected(bool stopCalled)
        {
            try
            {
                Cldb.Remove_connection_from_agenda_table(Context.ConnectionId);

                using (var db = new UserContext())
                {
                    var connection = db.Connections.Find(Context.ConnectionId);
                    connection.Connected = false;
                    connection.DeConnectionTime = DateTime.Now;
                    db.SaveChanges();
                }
            }
            catch (Exception e)
            {
                Cldb.Insert_error(e.Message.ToString() + " " + e.InnerException.ToString(), e.StackTrace.ToString(), "OnDisconnected");
            }

            return base.OnDisconnected(stopCalled);
        }

        [HubMethodName("updateAgenda")]
        public string UpdateAgenda()
        {
            using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings["QualiproConnection"].ConnectionString))
            {
                    connection.Open();

                    /*string query = "select [mat],[nb_formation] " +
                    ",[nb_audit],[nb_action],[nb_reunion],[nb_equipement] from dbo.[tab_agenda] where [mat]="+ Mat;
                    /*"[nb_fournisseur],[nb_reclamation],[nb_document],[nb_indicateur],[nb_non_conformite]," +
                    "[nb_environnement],[nb_haccp1],[nb_haccp2]," +
                    "[nb_coq],[nb_verif],[nb_courrier],[nb_habilitation]," +
                    "[nb_amdec],[nb_secur],[nb_conf_reg],[nb_part_int],[nb_risque]," +
                    "[nb_achat],[nb_doc_group],[nb_reunion_info]," +
                    "[nb_action_uni],[nb_changement] from dbo.[tab_agenda] ";*/

                    using (

                        //Solution 1 and 2 : Filter in the Original Query                        
                        //var command = new SqlCommand(@"select [mat],[nb_formation] ,[nb_audit],[nb_action],[nb_reunion],[nb_equipement] from dbo.[tab_agenda] where [ConnectionId]=@conId" , connection))

                        //Solution 2, : No Filter in the original Query 
                        var command = new SqlCommand("select [connectionId],[mat],[nb_formation] ,[nb_audit],[nb_action],[nb_reunion],[nb_equipement] from dbo.[tab_agenda]", connection))
                    {
                        // This is Not used any more, not working 
                        // command.Parameters.AddWithValue("@mat", Cldb.Get_client_mat(Context.ConnectionId));

                        // Solution 2: Filter parameter is hard coded => SQL DEPENDENCY WORKS
                        //command.Parameters.AddWithValue("@conId", "c6103452-8886-44d9-8ff2-5463884243c2");

                        //Solution 3 : Filter parameter coming from connectionId ==> data are displayed on start but then sql dependency is not updating the data
                        ////command.Parameters.AddWithValue("@conId", Context.ConnectionId);

                        /*string Id = ListUser.Find(x => x.ConnectionId == Context.ConnectionId).UserId;*/

                        //command.Parameters.AddWithValue("@conId", ConId);

                        command.Notification = null;
                        DataTable dt = new DataTable();
                        SqlDependency dependency = new SqlDependency(command);
                        dependency.OnChange += new OnChangeEventHandler(Dependency_OnChange);

                        if (connection.State == ConnectionState.Closed)
                            connection.Open();

                        var reader = command.ExecuteReader();
                        dt.Load(reader);

                        if (dt.Rows.Count > 0)
                        {
                            //Solution 3 : FILTERING the data using LINQ => SQL dependency is not working
                            //var dataRow = dt.AsEnumerable().Where(x => x.Field<string>("connectionId") == Context.ConnectionId).FirstOrDefault();

                            //Solution 4 : Filtering data using Dataview filer  => SQL dependency is not working
                            /*DataView dv = new DataView(dt)                            
                            {
                                RowFilter = "connectionId='" + Context.ConnectionId + "'"
                            };*/
                            //if (dv.Count > 0)

                            //if (dataRow != null)
                            {
                                //dt = dv.ToTable();
                                Mat = dt.Rows[0]["Mat"].ToString();
                                ConnectionId = dt.Rows[0]["ConnectionId"].ToString();
                                nb_formation = Int16.Parse(dt.Rows[0]["nb_formation"].ToString());
                                nb_audit = Int16.Parse(dt.Rows[0]["nb_audit"].ToString());
                                nb_action = Int16.Parse(dt.Rows[0]["nb_action"].ToString());
                                nb_equipement = Int16.Parse(dt.Rows[0]["nb_equipement"].ToString());
                                nb_reunion = Int16.Parse(dt.Rows[0]["nb_reunion"].ToString());

                                /*Mat = dataRow["Mat"].ToString();
                                ConnectionId = dataRow["ConnectionId"].ToString();
                                nb_formation = Int16.Parse(dataRow["nb_formation"].ToString());
                                nb_audit = Int16.Parse(dataRow["nb_audit"].ToString());
                                nb_action = Int16.Parse(dataRow["nb_action"].ToString());
                                nb_equipement = Int16.Parse(dataRow["nb_equipement"].ToString());
                                nb_reunion = Int16.Parse(dataRow["nb_reunion"].ToString());*/
                            }

                        }
                    }
                }
                IHubContext context = GlobalHost.ConnectionManager.GetHubContext<AgendaHub>();
                return context.Clients.All.recieveagenda(Mat, ConnectionId,nb_formation, nb_audit,nb_action,nb_equipement,nb_reunion);
        }

        private void Dependency_OnChange(object sender, SqlNotificationEventArgs e)
        {
                if (e.Type == SqlNotificationType.Change)
                {
                    AgendaHub nHub = new AgendaHub();
                    nHub.UpdateAgenda();
                }
        }
    }
}

The client:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>SignalR SQL Server dependancy Client</title>
    <style type="text/css">
        .auto-style1 {
            width: 166px;
        }
    </style>
</head>
    <script src='http://localhost:210/scripts/jquery-1.10.2.min.js' type="text/javascript"></script>     

    <script type="text/javascript">

        $.getScript('http://localhost:210/Scripts/jquery.signalR-2.1.1.min.js', function () {
            $.getScript('http://localhost:210/signalr/hubs', function () {
            // Declare a proxy to reference the hub.
            $.connection.hub.url = 'http://localhost:210/signalr';                
                var notifications = $.connection.agendaHub;
                $.connection.hub.qs = { 'uid': '100' };

            // Create a function that the hub can call to broadcast messages.
                notifications.client.recieveagenda = function (Mat, ConnectionId,nb_formation,nb_audit,nb_action,nb_equipement,nb_reunion)
            {
                // Add the message to the page.                   

                $('#spanconId').text($.connection.hub.id);              
                $('#span_conId').text(ConnectionId);
                $('#spanMat').text(Mat);
                $('#spannb_Formation').text(nb_formation);
                $('#spannb_Audit').text(nb_audit);
                $('#spannb_Reunion').text(nb_reunion);
                $('#spannb_Equipement').text(nb_equipement);
                $('#spannb_Action').text(nb_action);                
                };




            // Start the connection.
                $.connection.hub.start().done(function () {
                    alert("connection started");                   
                    notifications.server.updateAgenda();                   
            }).fail(function (e) {
                alert(e);
            });
            $.connection.hub.disconnected(function () { $.connection.hub.start();});


            //$.connection.hub.start();
            });
        });
</script>


<body>
    <form id="form1" runat="server">

        <h1>Notifications</h1>

<div>

    <table>
        <tr>
            <td><span  id="spanconId"></span></td>
        </tr>
    </table>
    <table border="1" style="width: 510px">
        <tr>
            <td class="auto-style1">ConnectionId</td>
            <td><span id="span_conId"></span></td>
        </tr>

        <tr>
            <td class="auto-style1">Mat</td>
            <td><span id="spanMat"></span></td>
        </tr>
        <tr>
            <td class="auto-style1">nb Formation</td>
            <td><span id="spannb_Formation"></span></td>
        </tr>

        <tr>
            <td class="auto-style1">nb Audit</td>
            <td><span id="spannb_Audit"></span></td>
        </tr>

        <tr>
            <td class="auto-style1">nb Action</td>
            <td><span id="spannb_Action"></span></td>
        </tr>

        <tr>
            <td class="auto-style1">nb Réunion</td>
            <td><span id="spannb_Reunion"></span></td>
        </tr>

        <tr>
            <td class="auto-style1">nb Equipement</td>
            <td><span id="spannb_Equipement"></span></td>
        </tr>



    </table>

</div>




    </form>

</body>
</html>

来源：https://stackoverflow.com/questions/59325162/filtering-data-table-inside-hub-class-prevents-sql-dependency-to-run

标签

sql-server

signalr

sqldependency