حساب مجموع ايام غياب موظف في شهر معين

كود :
 Dim zzz As Integer



                    Using connection = New OleDbConnection("provider=microsoft.jet.oledb.4.0;" & "data source=" & Application.StartupPath & "\db1.mdb")

                        Using command = New OleDbCommand("SELECT SUM(esas_no) As Total FROM lost_count where tch_no =" & TextBox2.Text.Trim & "and lost_date >= " & DateTimePicker1.Value.Date & "and lost_date <=" & DateTimePicker2.Value.Date & "", cn)





                            Dim total = Convert.ToInt32(command.ExecuteScalar)

                            If IsDBNull(total) Then

                                TextBox7.Text = 0

                            Else

                                zzz = total.ToString

                                TextBox7.Text = zzz

                            End If





                        End Using

                    End Using