Personalized push notification with SignalR and SqlDependency - asp.net

Question

We are working adding real time push notification to Asp.net web application.
I'm able to broadcast one message to all the users who is logged in to website.
but I'm not able to send notification to only one particular user based on the value inserted in the database table.
when i try to do this it's updating all the clients whoever is logged currently.
My code sample below:
SqlDependency Component:
Public Sub RegisterNotification(ByVal currentTime As DateTime)
Try
Dim conStr = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Dim sqlCommand = "SELECT [seq_id],[user_id],[create_timestamp],[alert_read] FROM [dbo].[tblAlerts] WHERE [alert_read]=0 AND [create_timestamp] > #AddedOn"
Using con As New SqlConnection(conStr)
Dim cmd As New SqlCommand(sqlCommand, con)
cmd.Parameters.AddWithValue("#AddedOn", currentTime)
If con.State <> Data.ConnectionState.Open Then
con.Open()
End If
cmd.Notification = Nothing
Dim dependency As New SqlDependency(cmd)
AddHandler dependency.OnChange, AddressOf sqlDep_OnChange
Using reader As SqlDataReader = cmd.ExecuteReader()
Do nothing here
End Using
End Using
Catch ex As Exception
Throw ex
End Try
End Sub
Sub sqlDep_OnChange(ByVal sender As Object, ByVal e As SqlNotificationEventArgs)
Try
If e.Info = SqlNotificationInfo.Insert Then
Dim notificationHub = GlobalHost.ConnectionManager.GetHubContext(Of NotificationHub)
Dim userid = Membership.GetUser.ProviderUserKey
notificationHub.Clients.All.notify(userid)
End If
Dim depend = DirectCast(sender, SqlDependency)
RemoveHandler depend.OnChange, AddressOf sqlDep_OnChange
RegisterNotification(DateTime.UtcNow)
Catch ex As Exception
End Try
End Sub
Notification Hub Code
Public Class NotificationHub
Inherits Hub
Public Sub showdata(ByVal obj As Object)
Try
Dim userobj = obj
Dim notificationHub = GlobalHost.ConnectionManager.GetHubContext(Of NotificationHub)
Dim count = 0
take count from database for userid in the object
notificationHub.Clients.All.setcount(count)
Catch ex As Exception
End Try
End Sub
End Class
SignalR Js code
$(function () {
// signalr js code for start hub and send receive notification
var notificationHub = $.connection.notificationHub;
notificationHub.client.setCount = function (data) {
$('span.count').html(data);
}
$.connection.hub.start().done(function () {
console.log('Notification hub started');
});
//signalr method for push server message to client
notificationHub.client.notify = function (message) {
if (message) {
notificationHub.server.showdata(message);
}
}
})
I have also noticed one more thing here is , sqlDep_OnChange event is called more than once if i have opened applicaiton in more than one browser.

Answer 1

I have managed to do the same with following link:
https://learn.microsoft.com/en-us/aspnet/signalr/overview/guide-to-the-api/mapping-users-to-connections
Using SignalR v2 you can use the connectionID to find the corresponding user.