SqlDependency not firing - sql

Question

I am trying SqlDepenedency for the first time. I am not getting any notifications on Database Update.
I am placing breakpoints inside :
OnChange(object sender, SqlNotificationEventArgs e),
but it never gets hit.
Here is my code :
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = "Cache Refresh: " + DateTime.Now.ToLongTimeString();
DateTime.Now.ToLongTimeString();
// Create a dependency connection to the database.
SqlDependency.Start(GetConnectionString());
using (SqlConnection connection = new SqlConnection(GetConnectionString()))
{
using (SqlCommand command = new SqlCommand(GetSQL(), connection))
{
SqlDependency dependency =
new SqlDependency(command);
// Refresh the cache after the number of minutes
// listed below if a change does not occur.
// This value could be stored in a configuration file.
connection.Open();
dgHomeRequests.DataSource = command.ExecuteReader();
dgHomeRequests.DataBind();
}
}
}
private string GetConnectionString()
{
// To avoid storing the connection string in your code,
// you can retrieve it from a configuration file.
//return "Data Source=(local);Integrated Security=true;" +"Initial Catalog=AdventureWorks;";
return ConfigurationManager.ConnectionStrings["TestData"].ConnectionString;
}
private string GetSQL()
{
return "Select [Address] From [UserAccount1]";
}
void OnChange(object sender, SqlNotificationEventArgs e)
{
// have breakpoint here:
SqlDependency dependency = sender as SqlDependency;
// Notices are only a one shot deal
// so remove the existing one so a new
// one can be added
dependency.OnChange -= OnChange;
// Fire the event
/* if (OnNewMessage != null)
{
OnNewMessage();
}*/
}
I have also placed some code in Global.asax file :
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
SqlDependency.Start(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
}
protected void Application_End()
{
// Shut down SignalR Dependencies
SqlDependency.Stop(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
}
}
The SQL server is on local machine. I am running the code through Visual Studio(IIS Express).
To enable service broker on database:
ALTER DATABASE SET ENABLE_BROKER
GO
To subscribe query notification, we need to give permission to IIS service account
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO “<serviceAccount>”
I guessed the 2nd point is not needed as it is local. But I tried giving it some permissions. Don't know if they are right as I don't think it is using app pool.And don't need the permission on local env. if I am the user myself and created the schema myself.
One of the questions that I saw was granting :
alter authorization on database::<dbName> to [sa];
I gave that permission too.

Answer 1

I was missing :
dependency.OnChange += new OnChangeEventHandler(OnChange);
The new code would look like :
SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(OnChange);
now I can fire
void OnChange(object sender, SqlNotificationEventArgs e)