vb.net ถามเรื่องการหา table หน่อยครับ ส่งค่ากลับมาว่ามีหรือไม่มี

 Dim check As Boolean = False
  sb.Remove(0, sb.Length)
                            sb.Append("select TOP 1 Doc_No from cg_pos_head where OU_Code='" + DataGridView2.Rows(b).Cells(0).Value.ToString() + "' order by Doc_No desc")
                            Dim sqlcg_pos_head As String = sb.ToString()
                            com = New SqlCommand
                            With com
                                .CommandType = CommandType.Text
                                .CommandText = sqlcg_pos_head
                                .Parameters.Clear()
                                .Connection = con
                                .Transaction = tr
                                dr = .ExecuteReader()
                                If dr.HasRows Then
                                    dt = New DataTable
                                    dt.Load(dr)
                                    batid = dt.Rows(0)("Doc_No").ToString()
                                    batid2 = CInt(batid) + 1
                                    batNO = batid2.ToString("000000")
                                Else
                                    batNO = batid2.ToString("000000")
                                End If
                                dr.Close()
                                check = True

                            End With
                            If check = True Then
                                Dim tatollvat As Double = CDbl(DataGridView2.Rows(b).Cells(2).Value)
                                sb.Remove(0, sb.Length)
                                sb.Append("select VAT_RATE from cg_shop where ou_code='" + DataGridView2.Rows(b).Cells(0).Value.ToString() + "'")
                                Dim sqlingood As String = sb.ToString()
                                com = New SqlCommand
                                With com
                                    .CommandType = CommandType.Text
                                    .CommandText = sqlingood
                                    .Connection = con
                                    .Transaction = tr
                                    .Parameters.Clear()
                                    dr = .ExecuteReader()
                                    If dr.HasRows Then
                                        dt = New DataTable
                                        dt.Load(dr)
                                        vat = CInt(dt.Rows(0)("VAT_RATE").ToString())
                                    End If
                                    dr.Close()
                                End With
                                sumvat = tatollvat * vat / 107
                               End If