Dim sql As String = "SELECT * FROM Tasks WHERE DueDate < @DueDate"
Using cn As New SqlConnection("Your connection string here"), _
    cmd As New SqlCommand(sql, cn)
    cmd.Parameters.Add("@DueDate", SqlDbType.DateTime).Value = DateTime.Now
    Dim reader As SqlDataReader = cmd.ExecuteReader
    While reader.Read
        Debug.WriteLine(reader(0))
    End While
End Using