Init SqlDependency and notify changes - sql-server-2008

Question

I need something telling to my app when someone has updated data in the database. If I don't have misunderstood, SqlDependancy is what I need. I have followed this tutorial and write this code:
class dbListener
{
public dbListener()
{
Debug.WriteLine(MainWindow.dbContext.Database.Connection.ConnectionString + "Password=12345;");
SqlDependency.Start(MainWindow.dbContext.Database.Connection.ConnectionString + "Password=12345;");
connection = new SqlConnection(MainWindow.dbContext.Database.Connection.ConnectionString + "Password=12345;");
connection.Open();
SomeMethod();
}
SqlConnection connection;
void SomeMethod()
{
// Assume connection is an open SqlConnection.
// Create a new SqlCommand object.
//{
using (SqlCommand command = new SqlCommand("SELECT * FROM dbo.ArchivioErogazioni", connection))
{
// Create a dependency and associate it with the SqlCommand.
SqlDependency dependency = new SqlDependency(command);
// Maintain the refence in a class member.
// Subscribe to the SqlDependency event.
dependency.OnChange += new OnChangeEventHandler(OnDependencyChange);
// Execute the command.
command.ExecuteReader();
// }
}
}
// Handler method
void OnDependencyChange(object sender, SqlNotificationEventArgs e)
{
if (e.Type == SqlNotificationType.Change)
{
// Handle the event (for example, invalidate this cache entry).
MessageBox.Show("ikjkjkj");
Debug.WriteLine("fkldjkfjklgjf");
SqlDependency dependency = (SqlDependency)sender;
dependency.OnChange -= OnDependencyChange;
SomeMethod();
}
}
void Termination()
{
// Release the dependency.
SqlDependency.Stop(MainWindow.GetConnectionString("Model"));
}
}
but it doesn't work. I mean, it runs without errors, but when I try to test it, updating some values from the SQL Server 2008 Management Studio, nothing happens. I have put a breakpoint in the function that would manage the event, but it is fired only in the init phase.
Have I done mistakes? How can I reach my goal?

Answer 1

but it is fired only in the init phase
It fires because your query notification subscription is invalid. You must inspect the SqlNotificationEventArgs members. Only the Change type is a notification for change, you are probably getting a Subscribe type with Statement source. Your query does not meet the criteria described in Creating a Query for Notification:
The statement may not use the asterisk (*) or table_name.* syntax to specify columns.