ขอแนวทางการลบข้อมูลในตารางที่อยู่ใน database โดยที่ถ้าข้อมูลในตารางที่ 1 ตรงกับข้อมูลในตารางที่ 2 ก็ให้ลบข้อมูลในตารางที่ 2 ครับ

      If Me.DataGridView2.Rows.Count <> 0 Then
             โค๊ตเดิมตอนที่แล้ว
            Dim start As Integer = DataGridView2.CurrentRow.Index
            For s As Integer = start To (start + CInt(Me.TextBox1.Text)) - 1
                Dim r = DataGridView1.RowCount
                DataGridView1.Rows.Add()
                DataGridView1.Rows(r).Cells(0).Value = DataGridView2.Rows(s).Cells(0).Value
            Next

             'เพิ่มเติมลบตารางออก
            For f As Integer = 0 To Me.DataGridView1.Rows.Count - 1
                For g As Integer = 0 To Me.DataGridView2.Rows.Count - 1
                    If Me.DataGridView1.Rows(f).Cells(0).Value = Me.DataGridView2.Rows(g).Cells(0).Value Then
                        
                         'ใส่ตรงนี้ก็ได้ครับ
                          sql = "DELETE FROM reservation WHERE id='" & Me.DataGridView2.Rows(g).Cells(0).Value & "';"
                           cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                            cn.open()
                            cmd.ExecuteNonQuery()
                            cn.close()
                            'จบส่วนลบในฐานข้อมูล

                           Me.DataGridView2.Rows.Remove(DataGridView2.Rows(g))
                        Exit For
                    End If
                Next
            Next
        End If

private void sett_Post_PostCodeBindingNavigatorSaveItem_Click(object sender, EventArgs e)
        {
            this.Validate();
            this.sett_Post_PostCodeBindingSource.EndEdit();
            this.tableAdapterManager.UpdateAll(this.postCodeDataSet);

        }

                    sql = "INSERT INTO reservation (xxx)VALUES(xxx);"
                     cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                      cn.open()
                      cmd.ExecuteNonQuery()
                      cn.close()
                     

                    sql = "DELETE FROM reservation WHERE id='" & Me.DataGridView2.Rows(g).Cells(0).Value & "';"
                     cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                      cn.open()
                      cmd.ExecuteNonQuery()
                      cn.close()
                    

sql = "insert into reservation (product_id, product_name, product_warehouse, product_amount, product_qty, product_lotno, product_color, product_date) values (@product_id, @product_name, @product_warehouse, @product_amount, @product_qty, @product_lotno, @product_color, @product_date)"
               Dim start As Integer = dgv1.CurrentRow.Index
               For i As Integer = start To (start + CInt(tb01.Text)) - 1
                   If Not dgv1.Rows(i).IsNewRow Then
                       cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                       With cmd
                           .Parameters.Add(New SqlParameter("@product_id", dgv1.Rows(i).Cells(0).Value))
                           .Parameters.Add(New SqlParameter("@product_name", dgv1.Rows(i).Cells(1).Value))
                           .Parameters.Add(New SqlParameter("@product_warehouse", dgv1.Rows(i).Cells(2).Value))
                           .Parameters.Add(New SqlParameter("@product_amount", dgv1.Rows(i).Cells(3).Value))
                           .Parameters.Add(New SqlParameter("@product_qty", dgv1.Rows(i).Cells(4).Value))
                           .Parameters.Add(New SqlParameter("@product_lotno", dgv1.Rows(i).Cells(5).Value))
                           .Parameters.Add(New SqlParameter("@product_color", dgv1.Rows(i).Cells(6).Value))
                           .Parameters.Add(New SqlParameter("@product_date", dgv1.Rows(i).Cells(7).Value))
                       End With
                       cmd.ExecuteNonQuery()
                   End If
               Next
    
   For f As Integer = 0 To Me.DataGridView1.Rows.Count - 1
          For g As Integer = 0 To Me.DataGridView2.Rows.Count - 1
             'ตรวจสอบว่าตารางรหัสของ Me.DataGridView1 เหมือนกับ Me.DataGridView2 ให้ลบตารางนั้นออก
              If Me.DataGridView1.Rows(f).Cells(0).Value = Me.DataGridView2.Rows(g).Cells(0).Value Then
                  
                   'ส่วนลบในฐานข้อมูล
                    sql = "DELETE FROM xxx WHERE id='" & Me.DataGridView2.Rows(g).Cells(0).Value & "';"
                     cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                      cn.open()
                      cmd.ExecuteNonQuery()
                      cn.close()
                      'จบส่วนลบในฐานข้อมูล
                     'ลบตารางในดาต้กริด DataGridView2
                     Me.DataGridView2.Rows.Remove(DataGridView2.Rows(g))
                  Exit For
              End If
          Next
      Next

               'MessageBox.Show("คุณได้ทำการจองสินค้าเรียบร้อยแล้ว")
           Catch ex As Exception
               MessageBox.Show(Err.Description)
           End Try

 Private Sub btnOK_Click(sender As Object, e As EventArgs) Handles btnOK.Click
        open_database()
        Try
            If dgv02.Rows.Count <> 0 Then
                
                Dim start As Integer = dgv02.CurrentRow.Index
                For i As Integer = start To (start + CInt(tb01.Text)) - 1
                    If Not dgv02.Rows(i).IsNewRow Then
                        sql = "insert into reservation (product_id, product_name, product_warehouse, product_amount, product_qty, product_lotno, product_color, product_date)" & _
                      "values (@product_id, @product_name, @product_warehouse, @product_amount, @product_qty, @product_lotno, @product_color, @product_date)"
                        cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                        With cmd
                            .Parameters.Add(New SqlParameter("@product_id", dgv02.Rows(i).Cells(0).Value))
                            .Parameters.Add(New SqlParameter("@product_name", dgv02.Rows(i).Cells(1).Value))
                            .Parameters.Add(New SqlParameter("@product_warehouse", dgv02.Rows(i).Cells(2).Value))
                            .Parameters.Add(New SqlParameter("@product_amount", dgv02.Rows(i).Cells(3).Value))
                            .Parameters.Add(New SqlParameter("@product_qty", dgv02.Rows(i).Cells(4).Value))
                            .Parameters.Add(New SqlParameter("@product_lotno", dgv02.Rows(i).Cells(5).Value))
                            .Parameters.Add(New SqlParameter("@product_color", dgv02.Rows(i).Cells(6).Value))
                            .Parameters.Add(New SqlParameter("@product_date", dgv02.Rows(i).Cells(7).Value))
                        End With
                        cmd.ExecuteNonQuery()
                    End If
                Next
            End If
            cn.Close()
        Catch ex As Exception
            MessageBox.Show(Err.Description)
        End Try

        If dgv02.Rows.Count > 0 Then
            Dim start1 As Integer = dgv02.CurrentRow.Index
            For i As Integer = start1 To (start1 + CInt(tb01.Text)) - 1
                If Not dgv02.Rows(i).IsNewRow Then
                    sql &= "delete from in_stock where id='" & dgv02.Rows(start1).Cells(0).Value & "';"
                    cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                End If
            Next
                End If
        load_dgv3()
        load_dgv2()
    End Sub

Private Sub btnOK_Click(sender As Object, e As EventArgs) Handles btnOK.Click
       open_database()
      
           If dgv02.Rows.Count <> 0 Then
               
               Dim start As Integer = dgv02.CurrentRow.Index
               For i As Integer = start To (start + CInt(tb01.Text)) - 1
                   If Not dgv02.Rows(i).IsNewRow Then
                       Try
                       sql = "insert into reservation (product_id, product_name, product_warehouse, product_amount, product_qty, product_lotno, product_color, product_date)" & _
                     "values (@product_id, @product_name, @product_warehouse, @product_amount, @product_qty, @product_lotno, @product_color, @product_date)"
                       cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                       With cmd
                           .Parameters.Add(New SqlParameter("@product_id", dgv02.Rows(i).Cells(0).Value))
                           .Parameters.Add(New SqlParameter("@product_name", dgv02.Rows(i).Cells(1).Value))
                           .Parameters.Add(New SqlParameter("@product_warehouse", dgv02.Rows(i).Cells(2).Value))
                           .Parameters.Add(New SqlParameter("@product_amount", dgv02.Rows(i).Cells(3).Value))
                           .Parameters.Add(New SqlParameter("@product_qty", dgv02.Rows(i).Cells(4).Value))
                           .Parameters.Add(New SqlParameter("@product_lotno", dgv02.Rows(i).Cells(5).Value))
                           .Parameters.Add(New SqlParameter("@product_color", dgv02.Rows(i).Cells(6).Value))
                           .Parameters.Add(New SqlParameter("@product_date", dgv02.Rows(i).Cells(7).Value))
                       End With
                       cmd.ExecuteNonQuery()
                       Catch ex As Exception
                       MessageBox.Show(ex.Message)
                       End Try

                      Try 
                  sql &= "delete from in_stock where id='" & dgv02.Rows(start).Cells(0).Value & "';"
                   cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                    cmd.ExecuteNonQuery()
                    Catch ex As Exception
                       MessageBox.Show(ex.Message)
                       End Try
                   End If
               Next
           End If
           cn.Close()
      
       load_dgv3()
       load_dgv2()
   End Sub

Private Sub btnOK_Click(sender As Object, e As EventArgs) Handles btnOK.Click
       open_database()
      
           If dgv02.Rows.Count <> 0 Then
               
               Dim start As Integer = dgv02.CurrentRow.Index
               For i As Integer = start To (start + CInt(tb01.Text)) - 1
                   If Not dgv02.Rows(i).IsNewRow Then
                       Try
                       sql = "insert into reservation (product_id, product_name, product_warehouse, product_amount, product_qty, product_lotno, product_color, product_date)" & _
                     "values (@product_id, @product_name, @product_warehouse, @product_amount, @product_qty, @product_lotno, @product_color, @product_date)"
                       cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                       With cmd
                           .Parameters.Add(New SqlParameter("@product_id", dgv02.Rows(i).Cells(0).Value))
                           .Parameters.Add(New SqlParameter("@product_name", dgv02.Rows(i).Cells(1).Value))
                           .Parameters.Add(New SqlParameter("@product_warehouse", dgv02.Rows(i).Cells(2).Value))
                           .Parameters.Add(New SqlParameter("@product_amount", dgv02.Rows(i).Cells(3).Value))
                           .Parameters.Add(New SqlParameter("@product_qty", dgv02.Rows(i).Cells(4).Value))
                           .Parameters.Add(New SqlParameter("@product_lotno", dgv02.Rows(i).Cells(5).Value))
                           .Parameters.Add(New SqlParameter("@product_color", dgv02.Rows(i).Cells(6).Value))
                           .Parameters.Add(New SqlParameter("@product_date", dgv02.Rows(i).Cells(7).Value))
                       End With
                       cmd.ExecuteNonQuery()
                       Catch ex As Exception
                       MessageBox.Show(ex.Message)
                       End Try

                      Try 
                  sql &= "UPDATE  in_stock SET reservations='1' where id='" & dgv02.Rows(start).Cells(0).Value & "';"
                   cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                    cmd.ExecuteNonQuery()
                    Catch ex As Exception
                       MessageBox.Show(ex.Message)
                       End Try
                   End If
               Next
           End If
           cn.Close()
      
       load_dgv3()
       load_dgv2()
   End Sub

 Dim start As Integer = dgv02.CurrentCell.RowIndex
                For i As Integer = start To (start + CInt(tb01.Text)) - 1
                    If Not dgv02.Rows(i).IsNewRow Then
                        sql = "insert into reservation (product_id, product_name, product_warehouse, product_amount, product_qty, product_lotno, product_color, product_date) values (@product_id, @product_name, @product_warehouse, @product_amount, @product_qty, @product_lotno, @product_color, @product_date)"
                        sql &= "delete from in_stock where product_id='" & dgv02.Rows(i).Cells(0).Value & "';"
                        'sql = "insert into in_stock(product_id, product_name, product_warehouse, product_amount, product_qty,product_lotno, product_color, product_date) values ('" & txtIDget.Text & "','" & txtPartget.Text & "','" & txtWhget.Text & "','" & txtAmountget.Text & "','" & txtQtyget.Text & "','" & txtLotget.Text & "','" & txtColorget.Text & "','" & DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") & "')"
                        cmd = New System.Data.SqlClient.SqlCommand(sql, cn)
                        With cmd
                            .Parameters.Add(New SqlParameter("@product_id", dgv02.Rows(i).Cells(0).Value))
                            .Parameters.Add(New SqlParameter("@product_name", dgv02.Rows(i).Cells(1).Value))
                            .Parameters.Add(New SqlParameter("@product_warehouse", dgv02.Rows(i).Cells(2).Value))
                            .Parameters.Add(New SqlParameter("@product_amount", dgv02.Rows(i).Cells(3).Value))
                            .Parameters.Add(New SqlParameter("@product_qty", dgv02.Rows(i).Cells(4).Value))
                            .Parameters.Add(New SqlParameter("@product_lotno", dgv02.Rows(i).Cells(5).Value))
                            .Parameters.Add(New SqlParameter("@product_color", dgv02.Rows(i).Cells(6).Value))
                            .Parameters.Add(New SqlParameter("@product_date", dgv02.Rows(i).Cells(7).Value))
                        End With
                        cmd.ExecuteNonQuery()
                    End If
                Next
                cn.Close()