สอบถามเรื่องวิธีการใช้งานคำสั่ง Throw มันขึ้น Error ว่า "OleDbException was unhandled"

Public Function GetAllDivision() As DataTable
  Try
    ........
   Catch ex
        Throw ex
   End Try
End Function

Public Function SomeFunction(...)
     Try
           dim dtable as DataTable = GetAllDivision()
     Catch ex
            ' Display error message here, do not throw any more
            MessageBox.Show(ex.Message)
     End Try
End Function

Public Function GetAllDivision() As DataTable
   ' Can write any code without try box
   '.......
End Function

Public Function SomeFunction(...)
     Try
           dim dtable as DataTable = GetAllDivision()
     Catch ex
            ' Display error message here, do not throw any more
            MessageBox.Show(ex.Message)
     End Try
End Function