sqldependency not detecting change. What am I missing?

Question

Im trying to check for any database changes using sqldependency and then send something to clients that are connected to signalr. The thing is, it seems that its not detecting changes. I feel theres something missing. heres the code:

[HubName("DataHub")]
public class DataHub : Hub
{
    public void pushOnChange() 
    {
        string connection = "data source=fourthD;initial catalog=dash;integrated security=True;multipleactiveresultsets=True;application name=EntityFramework"";
        SqlDependency.Start(connection);
        SqlConnection connectionString = new SqlConnection(connection);
        connectionString.Open();

        using (SqlCommand command=new SqlCommand("SELECT * FROM dbo.insight", connectionString))
        {
            command.Notification = null;
            SqlDependency dependency = new SqlDependency(command);
            dependency.OnChange += new OnChangeEventHandler(OnDependencyChange);
            command.ExecuteReader();
        }
    }


    void OnDependencyChange(object sender, SqlNotificationEventArgs e)
    {
        Dictionary<string, string> data = new Dictionary<string, string> { };
        data.Add("Id","34");
        data.Add("DeviceId", "163-117")
        data.Add("DeviceUserName", "Someone");

        var result = new[] { data };

        Clients.All.addData(result);
    }
}

Answer 1

The problem is that SqlDependency requires resubscription. So, you should modify your OnDependencyChange method like this:

void OnDependencyChange(object sender, SqlNotificationEventArgs e)
{
    // Resubscription
    using (SqlCommand command=new SqlCommand("SELECT * FROM dbo.insight"
            , connectionString))
    {
        command.Notification = null;
        SqlDependency dependency = new SqlDependency(command);
        dependency.OnChange += new OnChangeEventHandler(OnDependencyChange);
        command.ExecuteReader();
    }

    Dictionary<string, string> data = new Dictionary<string, string> { };
    data.Add("Id","34");
    data.Add("DeviceId", "163-117")
    data.Add("DeviceUserName", "Someone");

    var result = new[] { data };

    Clients.All.addData(result);
}

Hope this helps.