point of sale in visual basic

7/30/2019 Point of Sale in Visual Basic

1/12

Point of Sale in Visual Basic (Part 1)Next

Hello tyrodeveloper's, here is my first english publication, i hope that you like.

Requirements: Microsoft Visual Studio 2010

Microsoft Access 2007/2010

Data Base Design

We need to create a database like is showed in the picture:

Project creation

We create a project called PointOfSale:

Here is the project organization:
http://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-2.htmlhttp://4.bp.blogspot.com/-X6n8cp4BhA8/T1kmgsNCBaI/AAAAAAAABZY/pRr9MdxNLk4/s1600/PointOfSale02.jpghttp://4.bp.blogspot.com/-b-BAgsdL_jA/T1kmgZj7GJI/AAAAAAAABZM/EwdXLOVLFQQ/s1600/PointOfSale01.jpghttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-2.html


2/12

We have three folders. Add two forms to the Forms folder and a module in the Modules

folder like is showed in the picture.

Login Form (frmLogin)

Add this Imports directives:

Imports System.DataImports System.Data.OleDb

Add this Variables:

''Variables Dim Attempts AsInteger = 0 PublicShared UserLogin AsString

PublicShared FirstName AsString PublicShared LastName AsString PublicShared Sales AsBoolean PublicShared Reporting AsBoolean PublicShared Management AsBoolean PublicShared Catalog AsBoolean PublicShared Access AsBoolean

Open the modMain.vb module and add this code:

Module modMain Public CnnStr AsString = "Provider=Microsoft.ACE.OLEDB.12.0;" & _ "Data Source=C:\Users\ddi-gcastillo\" & _ "Documents\tyrodeveloper\PointOfSale\PointOfSale.accdb;" & _ "Persist Security Info=False;" Sub Main() Dim loginFrm AsNew frmLogin

loginFrm.StartPosition = FormStartPosition.CenterScreenApplication.Run(loginFrm)

If (frmLogin.Access = True) Then Dim mainFrm AsNew mdiMain

mainFrm.StartPosition = FormStartPosition.CenterScreenmainFrm.WindowState = FormWindowState.MaximizedApplication.Run(mainFrm)

ElseApplication.Exit()

EndIf EndSubEndModule

Design the login form like this:
http://2.bp.blogspot.com/-rU_qSrwA54o/T1kmg2gfpDI/AAAAAAAABZk/4HS5fkVaq98/s1600/PointOfSale03.jpg


3/12

On the frmLogin.vb form, add this function:

ProtectedFunction Login() AsBoolean Dim cnn AsNew OleDbConnection(CnnStr) Try

cnn.Open() Dim cmd AsNew OleDbCommand

cmd.Connection = cnncmd.CommandText = "SELECT * FROM USERS " & _

" WHERE USER_LOGIN=@user_login " & _ " AND USER_PASSWORD=@user_password"

cmd.Parameters.Add("@user_login",OleDbType.VarChar, 50).Value = txtUserLogin.Text

cmd.Parameters.Add("@user_password",OleDbType.VarChar, 255).Value = txtUserPassword.Text

Dim dr As OleDbDataReader = cmd.ExecuteReader If dr.Read Then

UserLogin = dr("USER_LOGIN").ToString()FirstName = dr("FIRST_NAME").ToString()LastName = dr("LAST_NAME").ToString()Sales = CBool(dr("SALES"))Reporting = CBool(dr("REPORTING"))Management = CBool(dr("MANAGEMENT"))Catalog = CBool(dr("CATALOG"))

Else

Attempts += 1 Throw (New Exception( _ "Username or password incorrect")) EndIf

dr.Close() ReturnTrue Catch ex As Exception Throw (ex) Finally

cnn.Close() EndTry EndFunction

And here is the code for the Ok button:

PrivateSub btnOk_Click(ByVal sender As System.Object, _

ByVal e As System.EventArgs) _ Handles btnOk.Click Try If (Attempts >= 3) Then

Access = FalseMessageBox.Show("Attempts exceeded", _

"System Information", _MessageBoxButtons.OK, _MessageBoxIcon.Error)

Me.Close() Else

Access = Login() If (Access) Then Me.Close() EndIf EndIf

Catch ex As ExceptionMessageBox.Show(ex.Message,

"System Information", _
http://2.bp.blogspot.com/-hHrXZ3AaJlk/T1kmgx1Du2I/AAAAAAAABZs/TydIM4ydVl0/s1600/PointOfSale04.jpg


4/12

MessageBoxButtons.OK,MessageBoxIcon.Error)

EndTry EndSub

Go to the project configuration and set:

Point of Sale in Visual Basic (Part 2)Previous|Next

Add two new forms (frmSale, frmPayment) like:

Design mdiMain like the picture:
http://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-1.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-3.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-3.htmlhttp://4.bp.blogspot.com/-hkJim8KsLhg/T1kvAGx0IUI/AAAAAAAABaI/t0meoHhA0C8/s1600/PointOfSale06.jpghttp://1.bp.blogspot.com/-8okttBHyT9g/T1kmhMPpsgI/AAAAAAAABZ8/DyLweSR-VaM/s1600/PointOfSale05.jpghttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-1.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-3.html


5/12

Add this code on the "Form_Load":

''AllowsmnuSales.Visible = frmLogin.SalesbtnSales.Visible = frmLogin.SalesmnuReporting.Visible = frmLogin.ReportingmnuManagement.Visible = frmLogin.ManagementmnuCatalog.Visible = frmLogin.Catalog


Payment Window (frmPayment)

Design the payment form like the picture :

Add three properties:

Protected _success AsBoolean = False PublicReadOnlyProperty Success AsBoolean Get

Return _success EndGet EndProperty
http://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-2.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-4.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-4.htmlhttp://4.bp.blogspot.com/-rfG72R84Ap0/T1k7bEzYRsI/AAAAAAAABag/Bs4skG_Irvc/s1600/PointOfSale08.jpghttp://4.bp.blogspot.com/-PD3J9E8qCt8/T1kvATCLPXI/AAAAAAAABaU/Lkri4srs5Yk/s1600/PointOfSale07.jpghttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-2.htmlhttp://www.tyrodeveloper.com/2012/03/point-of-sale-in-visual-basic-part-4.html


6/12

Protected _idSale AsInteger = 0 PublicReadOnlyProperty IdSale AsInteger Get Return _idSale EndGet EndProperty PublicProperty TotalSale AsDouble Get Return varTotal EndGet Set(ByVal value AsDouble)

varTotal = value EndSet EndProperty Dim varTotal AsDouble = 0

This is the function that saves the Sales:

ProtectedFunction DoSale() AsBoolean Dim cnn AsNew OleDbConnection(CnnStr) Dim RowCount AsInteger = 0 Dim varFolioVenta AsInteger = 0

_idSale = 0

Trycnn.Open()

Dim tran As OleDbTransaction = cnn.BeginTransaction() Dim cmd AsNew OleDbCommand

cmd.Connection = cnncmd.Transaction = tran

Try ''validate if exists product

cmd.CommandText = "SELECT COUNT(*) " & _ "FROM SALE_DETAIL_TMP " & _ " WHERE USER_LOGIN=@USER_LOGIN"

cmd.Parameters.Add("@USER_LOGIN", OleDbType.VarChar, _50).Value = frmLogin.UserLogin

RowCount = CInt(cmd.ExecuteScalar)cmd.Parameters.Clear() ''Clerar parems

If (RowCount = 0) Then

Throw (New Exception("No Data")) EndIf ''insert the sale

cmd.CommandText = "INSERT INTO SALE" & _ "(USER_LOGIN,REG_DATE," & _ " SALE_DATE,TOTAL,CASH,CHANGE)" & _ " VALUES (@USER_LOGIN,NOW(),NOW()," & _ " @TOTAL,@CASH,@CHANGE)"

cmd.Parameters.Add("@USER_LOGIN", _OleDbType.VarChar, 50).Value = frmLogin.UserLogin

cmd.Parameters.Add("@TOTAL", _OleDbType.Double).Value = varTotal

cmd.Parameters.Add("@CASH", _OleDbType.Double).Value = txtCash.Text

cmd.Parameters.Add("@CHANGE", _OleDbType.Double).Value = _

CDbl(txtCash.Text) - varTotal

cmd.ExecuteNonQuery()cmd.Parameters.Clear() ''clear params

''get the Idcmd.CommandText = "SELECT @@IDENTITY"varFolioVenta = CInt(cmd.ExecuteScalar())

''insert sale detailcmd.CommandText = "INSERT INTO SALE_DETAIL" & _

" (ID_SALE,ID_PRODUCT,QUANTITY," & _ " SALE_PRICE,TAX,BUY_PRICE)" & _ " SELECT @ID_SALE, ID_PRODUCT,QUANTITY," & _ " SALE_PRICE,TAX," & _ " BUY_PRICE FROM SALE_DETAIL_TMP " & _ " WHERE USER_LOGIN=@USER_LOGIN"

cmd.Parameters.Add("@ID_VENTA", _OleDbType.Integer).Value = varFolioVenta

cmd.Parameters.Add("@USER_LOGIN", _

OleDbType.VarChar, 50).Value = frmLogin.UserLogincmd.ExecuteNonQuery()cmd.Parameters.Clear() ''Clear params


7/12

''Update the Stockcmd.CommandText = "UPDATE PRODUCTS " & _

" INNER JOIN SALE_DETAIL_TMP " & _ " ON PRODUCTS.ID_PRODUCT = " & _ " SALE_DETAIL_TMP.ID_PRODUCT " & _ " SET PRODUCTS.STOCK = " & _ " PRODUCTS.STOCK-SALE_DETAIL_TMP.QUANTITY" + " WHERE ((SALE_DETAIL_TMP.USER_LOGIN= @USER_LOGIN));"


cmd.ExecuteNonQuery()cmd.Parameters.Clear() ''Clear Params

''delete the temp tablecmd.CommandText = "DELETE FROM SALE_DETAIL_TMP " & _

"WHERE USER_LOGIN=@USER_LOGIN"cmd.Parameters.Add("@USER_LOGIN", _

OleDbType.VarChar, 50).Value = frmLogin.UserLogincmd.ExecuteNonQuery()_idSale = varFolioVenta ''set the IDtran.Commit()

ReturnTrue Catch ex1 As OleDb.OleDbException

tran.Rollback() Throw (ex1)

EndTry Catch ex As Exception Throw (ex) Finally


The "Ok" button:

PrivateSub btnOk_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles btnOk.Click Try

_success = DoSale() If (_success) Then

Me.Close() EndIf Catch ex As Exception

MessageBox.Show(ex.Message, "System Information",MessageBoxButtons.OK, MessageBoxIcon.Error)

EndTry EndSub

The "Cancel" button:

PrivateSub btnCancel_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles btnCancel.Click

_success = False Me.Close() EndSub

The "txtCash" TextBox, when a key is pressed:

PrivateSub txtCash_TextChanged(ByVal sender AsObject, _ ByVal e As System.EventArgs) Handles txtCash.TextChanged Try Dim varCambio AsDouble = _

Convert.ToDouble(txtCash.Text) - varTotal If (varCambio >= 0) Then

txtChange.Text = String.Format("{0:C}",(Convert.ToDouble(txtCash.Text) - varTotal))

btnOk.Enabled = True Else

btnOk.Enabled = False EndIf Catch ex As Exception

txtCash.Text = ex.MessagebtnOk.Enabled = False

EndTry


8/12

EndSub

The "Form_Load";

PrivateSub frmPayment_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) HandlesMyBase.Load Try

txtTotal.Text = String.Format("{0:C}", varTotal)txtTotal.Enabled = FalsetxtChange.Enabled = FalsetxtCash.Text = varTotal.ToString()

Catch ex As ExceptionMessageBox.Show(ex.Message, "System Information",MessageBoxButtons.OK, MessageBoxIcon.Error)

EndTry EndSub


Sales window (frmSale)

Design the form like the picture:

Declare a variable to store the total:

Dim varTotal AsDouble = 0

The Sales logic process:

1.Type the Product ID and the Quantity

2.Validate if the Product exists on the Products Catalog.

3.

4.

If the Product does not exists generate an exception (Throw)

5.6.

7.Validate if the product exists in the temporal sales list.

8.

9.
http://www.blogger.com/point-of-sale-in-visual-basic-part-3.htmlhttp://1.bp.blogspot.com/-vnrxgxTSQ9M/T1k-XHn9dEI/AAAAAAAABas/8XjtIJImEkY/s1600/PointOfSale09.jpghttp://www.blogger.com/point-of-sale-in-visual-basic-part-3.html


9/12

If not exists, add new.

10.

If exists, update the Quantity

11.12.

The function to add items to the temporal sales list:

ProtectedFunction AddItem() AsBoolean Dim cnn AsNew OleDbConnection(CnnStr) Dim RowCount AsInteger = 0 Try


cmd.Connection = cnn ''Validate if the product exists

cmd.CommandText = "SELECT COUNT(*) FROM PRODUCTS " & _

"WHERE ID_PRODUCT=@ID_PRODUCT"cmd.Parameters.Add("@ID_PRODUCT", _OleDbType.VarChar, 50).Value = txtIdProduct.Text

RowCount = CInt(cmd.ExecuteScalar)cmd.Parameters.Clear() ''Clear params

If (RowCount = 0) Then Throw (New Exception("The product does not exists")) EndIf ''Validate if the product is in the sales list

cmd.CommandText = "SELECT COUNT(*) " & _ " FROM SALE_DETAIL_TMP " & _ " WHERE ID_PRODUCT=@ID_PRODUCT" & _ " AND USER_LOGIN=@USER_LOGIN"

cmd.Parameters.Add("@ID_PRODUCT", _OleDbType.VarChar, 50).Value = txtIdProduct.Text


RowCount = CInt(cmd.ExecuteScalar)cmd.Parameters.Clear() ''Clear params

If (RowCount = 0) Then ''Insert New

cmd.CommandText = "INSERT INTO SALE_DETAIL_TMP " & _ " (USER_LOGIN, ID_PRODUCT,QUANTITY," & _ "SALE_PRICE,BUY_PRICE,TAX) " & _ " SELECT @USER_LOGIN, ID_PRODUCT, @QTY, " & _ " SALE_PRICE, BUY_PRICE, TAX " & _ " FROM PRODUCTS WHERE ID_PRODUCT=@ID_PRODUCT"


cmd.Parameters.Add("@QTY", _OleDbType.Double).Value = txtQuantity.Text

cmd.Parameters.Add("@ID_PRODUCT", _OleDbType.VarChar, 50).Value = txtIdProduct.Text

Else ''Edit Quantity

cmd.CommandText = "UPDATE SALE_DETAIL_TMP " & _ " SET QUANTITY = QUANTITY + @QTY " & _ " WHERE ID_PRODUCT=@ID_PRODUCTO " & _ " AND USER_LOGIN=@USER_LOGIN "

cmd.Parameters.Add("@QTY",OleDbType.Double).Value = txtQuantity.Text

cmd.Parameters.Add("@ID_PRODUCT",OleDbType.VarChar, 50).Value = txtIdProduct.Text

cmd.Parameters.Add("@USER_LOGIN",OleDbType.VarChar, 50).Value = frmLogin.UserLogin

EndIfcmd.ExecuteNonQuery()

ReturnTrue Catch ex As Exception Throw (ex) Finally

cnn.Close()


10/12

EndTry EndFunction

The code to cancel the sales is:

ProtectedFunction CancelSale() AsBoolean Dim cnn AsNew OleDbConnection(CnnStr) Try


cmd.Connection = cnncmd.CommandText = "DELETE FROM SALE_DETAIL_TMP " & _

"WHERE USER_LOGIN=@USER_LOGIN"cmd.Parameters.Add("@USER_LOGIN",

OleDbType.VarChar, 50).Value = frmLogin.UserLogincmd.ExecuteNonQuery()

ReturnTrue Catch ex As Exception Throw (ex) Finally


To generate the ListView headers:

ProtectedSub Headers() With lvSale

.View = View.Details

.FullRowSelect = True

.GridLines = True

.HideSelection = False

.Columns.Add("Id", 50)

.Columns.Add("Product", 250)

.Columns.Add("Qty", 50, HorizontalAlignment.Right)

.Columns.Add("Price", 50, HorizontalAlignment.Right)

.Columns.Add("Total", 80, HorizontalAlignment.Right) EndWith

EndSub

To display the temporal sale items:

ProtectedSub DisplaySale() Dim cnn AsNew OleDbConnection(CnnStr)

varTotal = 0 Try


cmd.Connection = cnncmd.CommandText = "SELECT P.ID_PRODUCT, " & _

"P.PRODUCT, T.QUANTITY, T.SALE_PRICE," & _ "(T.QUANTITY * T.SALE_PRICE) AS TOTAL " & _ " FROM SALE_DETAIL_TMP T, PRODUCTS P " & _ " WHERE T.ID_PRODUCT=P.ID_PRODUCT " & _

" AND T.USER_LOGIN=@USER_LOGIN"cmd.Parameters.Add("@USER_LOGIN",

OleDbType.VarChar, 50).Value = frmLogin.UserLogin Dim dr As OleDbDataReader = cmd.ExecuteReader Dim i AsInteger = 0

lvSale.Items.Clear() While (dr.Read()) With lvSale

.Items.Add(dr("ID_PRODUCT").ToString())

.Items(i).SubItems.Add(dr("PRODUCT").ToString())

.Items(i).SubItems.Add(String.Format("{0:N}",dr("QUANTITY")))

.Items(i).SubItems.Add(String.Format("{0:C}",dr("SALE_PRICE")))

.Items(i).SubItems.Add(String.Format("{0:C}",dr("TOTAL")))

EndWithvarTotal += CDbl(dr("TOTAL"))i += 1


11/12

EndWhiledr.Close()lblTotal.Text = String.Format("{0:C}", varTotal)

Catch ex As Exception Throw (ex) Finally

cnn.Close() EndTry EndSub

The "Add" button:

PrivateSub btnAdd_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles btnAdd.Click Try If (AddItem()) Then

DisplaySale()txtQuantity.Text = "1"txtIdProduct.Text = ""txtIdProduct.Focus()

EndIf Catch ex As Exception

MessageBox.Show(ex.Message, "System Information",

MessageBoxButtons.OK, MessageBoxIcon.Error) EndTry EndSub

The "Cancel" button:

PrivateSub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click Try If (CancelSale()) Then

lvSale.Items.Clear() EndIf Catch ex As Exception

MessageBox.Show(ex.Message, "System Information",MessageBoxButtons.OK, MessageBoxIcon.Error)

EndTry EndSub

The "Payment" button:

PrivateSub btnPayment_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPayment.Click If (lvSale.Items.Count > 0) Then Dim frm AsNew frmPayment

frm.TotalSale = varTotalfrm.StartPosition = FormStartPosition.CenterScreenfrm.ShowInTaskbar = Falsefrm.ShowDialog()

If (frm.Success) ThenlvSale.Items.Clear()

EndIf

ElseMessageBox.Show("No items", "System Information",

MessageBoxButtons.OK, MessageBoxIcon.Error) EndIf EndSub

The "Form_Load" method:

PrivateSub frmSale_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.Load Try

Headers()DisplaySale()

Catch ex As ExceptionMessageBox.Show(ex.Message, "System Information", _

MessageBoxButtons.OK, MessageBoxIcon.Error) EndTry EndSub


12/12

It is the end of the Sales process. After we do the reports using the Visual Studio Reporting

options (rdlc reports).

Thanks...