title: Receiving NOTIFY payloads via nPgSQL
body: <p>At present, I am using <code>NPGSQL</code> connector for connecting the PostgreSQL database with my application which is written in <code>VB.Net</code>. </p>
  
  <p>I tried to <code>NOTIFY</code> the table changes for particular tables to the front-end using PostgreSQL's <code>LISTEN</code> and <code>NOTIFY</code> features. I got a positive outcome from that try. I successfully got notified from the back-end to the front end. For achieving that I tried out the following:</p>
  
  <pre><code>Public Sub test()
  
  Dim conn = New NpgsqlConnection("Server=servername;port=portNo; _
             User Id=UID;pwd=PWD;DataBase=DB;")
  conn.Open()
  
  Dim command = New NpgsqlCommand("listen notifytest;", conn)
  command.ExecuteNonQuery()
  
  
  AddHandler conn.Notification, AddressOf NotificationSupportHelper
  
  command = New NpgsqlCommand("notify notifytest;", conn)
  command.ExecuteNonQuery()
  
  End Sub
  
  Private Sub NotificationSupportHelper(ByVal sender As Object, _
                                        ByVal e As NpgsqlNotificationEventArgs)
  
  'Notified here.
  
  End Sub
  </code></pre>
  
  <p>This is working fine, but, PostgreSQL has a brand new feature for notify where the notify can have a payload, like <code>NOTIFY test, 'Hello world'</code> (where Hello world is the payload, in other words, additional information). </p>
  
  <p>I want to get that additional information in the Notification event handler <code>NotificationSupportHelper</code>. So in order to get that I just tried to access the members of <code>NpgsqlNotificationEventArgs</code>. But i got failed in that try, because it only contains PID and Condition as its members. So I decided to have a look at the <a href="http://npgsql.projects.pgfoundry.org/docs/api/index.html" rel="nofollow">NPGQL documentation</a>, from there, i got, there is no way to get additional information in NPGSQL vers 1.0. But they are providing an additional member for <code>NpgsqlNotificationEventArgs</code> called <a href="http://npgsql.projects.pgfoundry.org/docs/api/index.html" rel="nofollow">AdditionalInformation</a> in their 2nd release (NPGSQL V 2.0). But it also currently under construction. this property will return String.Empty always(From the <a href="http://npgsql.projects.pgfoundry.org/docs/api/index.html" rel="nofollow">docs</a>).</p>
  
  <p>So i hope you people understood what i am trying to accomplish, I just needed to receive the <code>payload</code> in the front end when ever a <code>notification</code> got raised. Does anybody know how to achieve my requirement? Is there any other <code>connector</code> available rather than <code>NPGSQL</code> to handle <code>notification event</code> in the front end effectively, meaning getting the <code>payload</code> in the front end.?</p>