รบกวนสอบถามการตัดสต๊อกโดยใช้นำข้อมูลจากสองตารางมาบวกลบกัน ด้วยวิธีบวกลบ cell ใน datagrid ครับ

Option Explicit On
Option Strict On
Imports System.IO
Imports System.Text
Imports System.Data
Imports System.Data.SqlClient
Imports System.Drawing.Drawing2D

Public Class Form1
    Dim Conn As SqlConnection
    Dim com As SqlCommand
    Dim tr As SqlTransaction
    Dim sb As StringBuilder
    Dim dr As SqlDataReader

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim strConn As String
        strConn = DBConnString.strConn

        Conn = New SqlConnection()
        With Conn
            If .State = ConnectionState.Open Then .Close()
            .ConnectionString = strConn
            .Open()
        End With
        showdata1()
        showdata2()
        FormatDgvEquipment()
        FormatDgvTransport()


    End Sub

    Private Sub showdata1()
        Dim sqlEquipment As String
        sqlEquipment = "SELECT * FROM Equipment ORDER BY EqmID"
        Dim dr As SqlDataReader
        Dim dt As DataTable
        com = New SqlCommand()
        With com
            .CommandType = CommandType.Text
            .CommandText = sqlEquipment
            .Connection = Conn
            dr = .ExecuteReader()
            If dr.HasRows Then
                dt = New DataTable()
                dt.Load(dr)
                dgvEquipment.DataSource = dt
            Else
                dgvEquipment.DataSource = Nothing
            End If
        End With
        dr.Close()
    End Sub

    Private Sub showdata2()
        Dim sqlView_1 As String
        sqlView_1 = "SELECT * FROM View_2 ORDER BY TrID"
        Dim dr As SqlDataReader
        Dim dt As DataTable
        com = New SqlCommand()
        With com
            .CommandType = CommandType.Text
            .CommandText = sqlView_1
            .Connection = Conn
            dr = .ExecuteReader()
            If dr.HasRows Then
                dt = New DataTable()
                dt.Load(dr)
                dgvTransport.DataSource = dt
            Else
                dgvTransport.DataSource = Nothing
            End If
        End With
        dr.Close()
    End Sub

    Private Sub FormatDgvEquipment()
        With dgvEquipment
            If .RowCount > 0 Then
                .Columns(0).Width = 70
                .Columns(1).Width = 120
                .Columns(2).Width = 100
                .Columns(3).Width = 90
                .Columns(4).Width = 90
                .Columns(5).Width = 90
                .Columns(6).Width = 90
            End If
        End With
    End Sub

    Private Sub FormatDgvTransport()
        With dgvTransport
            If .RowCount > 0 Then
                .Columns(0).Width = 70
                .Columns(1).Width = 90
                .Columns(2).Width = 120
                .Columns(3).Width = 80
                .Columns(4).Width = 80
                .Columns(5).Width = 80
                .Columns(6).Width = 180
                .Columns(7).Width = 80
                .Columns(8).Width = 90
                .Columns(9).Width = 70
                .Columns(10).Width = 100

            End If
        End With
    End Sub
    Private Sub Form1_FormClosed(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        If Conn IsNot Nothing Then
            Conn.Close()
        End If
    End Sub
   
    Private Sub btnSave_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSave.Click

    End Sub
End Class