Programmer's Highway

Imports System.Data.SqlClient

    Private sqlDependency As SqlDependency
     
    ''' <summary>
    ''' Query Notification
    ''' </summary>
    Private Sub button1_Click(sender As Object, e As EventArgs)
        ' Connection Strings
        Dim connectionString As String = "Data Source=127.0.0.7;Initial Catalog=TestDatabase;Integrated Security=True;"
    
        ' Start SqlDependency.
        sqlDependency.Start(connectionString)
    
        Using sqlConnection As New SqlConnection(connectionString)
            Using sqlCommand As SqlCommand = sqlConnection.CreateCommand()
                sqlConnection.Open()
                sqlCommand.CommandText = "SELECT Student.Name, Student.Sex, Student. FROM dbo.Student"
    
                ' Register the event handler.
                Me.sqlDependency = New SqlDependency(sqlCommand)
                AddHandler Me.sqlDependency.OnChange, AddressOf OnChange
    
                ' If you need a query, call sqlCommand.ExecuteReader()
                sqlCommand.ExecuteNonQuery()
            End Using
        End Using
    End Sub
    
    ''' <summary>
    ''' Query Notification Event
    ''' </summary>
    Private Sub OnChange(sender As Object, e As EventArgs)
        System.Diagnostics.Debug.WriteLine("OnChange")
    
        ' If you do not need any more delete event
        RemoveHandler Me.sqlDependency.OnChange, AddressOf OnChange
    End Sub