Imports ADOX
Imports System.IO
Imports System.Data.OleDb
Imports System.Text
Imports System.Security.Cryptography



Public Class LogIn
    Public ConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
    Dim cat As Catalog = New Catalog()
    Dim SQLCommand As String
    Dim con As New OleDbConnection(ConnectionString)
    Dim cmd As New OleDbCommand
    Dim uname As String
    Dim pword As String

    'This sub creates all the tables within the database
    Private Sub LogIn_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim cat As Catalog = New Catalog()
        Dim SQLCommand As String = "CREATE TABLE Staff(Username VarChar(255), Pword VarChar(255));"

        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand
        If File.Exists("N:\TestDatabase.accdb") = True Then
            MsgBox("already exists")
        Else
            cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;" & _
                        "Data Source=N:\TestDatabase.accdb;" & _
                        "Jet OLEDB:Engine Type=5")
            MsgBox("Made")

            cat = Nothing
        End If

            con.Open()
            cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        cmd.ExecuteNonQuery()

        uname = "Admin"
        pword = HashPass("pass1")
        cmd.CommandText = "INSERT INTO Staff(Username, Pword) VALUES ('" & uname & "','" & pword & "')"
        cmd.ExecuteNonQuery()
        con.Close()

        CreateAllTables()

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogin.Click
        CheckLogIn()
    End Sub
    ' This sub checks if the password and login that have been entered are equal to the one in the Staff table.
    Private Sub CheckLogIn()
        Dim uname As String = "Admin"

        If txtpassword.Text = "pass1" Then
            pword = HashPass("pass1")
        End If

        Dim pass As String
        If txtusername.Text = "" Or txtpassword.Text = "" Then
            MsgBox("Please fill in all the provided fields to continue!")
        Else

            Dim querry As String = "Select pword From Staff where Username= '" & uname & "';"
            Dim dbsource As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb"
            Dim conn = New OleDbConnection(dbsource)
            Dim cmd As New OleDbCommand(querry, conn)
            conn.Open()
            Try
                pass = cmd.ExecuteScalar().ToString
            Catch ex As Exception
                MsgBox("Username does not exit")
            End Try
            If (pword = pass) Then
                MsgBox("Login success")
                Main_Menu.Show()
                If Main_Menu.Visible Then
                    Me.Hide()
                End If

            Else
                MsgBox("login Failed")
                txtusername.Clear()
                txtpassword.Clear()
            End If
        End If

        con.Close()

    End Sub
    ' Grade A Hashing Function
    Private Function HashPass(ByVal Content As String) As String
        Dim MoLeCuL3 As New Security.Cryptography.SHA1CryptoServiceProvider
        Dim ByteString() As Byte = System.Text.Encoding.ASCII.GetBytes(Content)
        ByteString = MoLeCuL3.ComputeHash(ByteString)

        Dim FinalString As String = Nothing
        For Each bt As Byte In ByteString
            FinalString &= bt.ToString("x2")
        Next
        Return FinalString
    End Function
    'Grade A Using SQL
    ' This Sub creates all the tables within the database.
    Private Sub CreateAllTables()
        SQLCommand = "CREATE TABLE Supplier(SupplierID varchar(255) PRIMARY KEY, BusinessName VarChar(255), ContactName Varchar(255)," &
            "BusinessEmail Varchar(255), BusinessAddress Varchar(255), BusinessCity Varchar(255), BusinessPostcode Varchar(255));"

        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Try
            cmd.ExecuteNonQuery()
        Catch ex As Exception
        End Try
        con.Close()



        SQLCommand = "CREATE TABLE Customer(CustomerID varchar(255) PRIMARY KEY, FirstName VarChar(255), LastName Varchar(255), Email Varchar(255)," &
            "Address Varchar(255), City Varchar(255), Postcode Varchar(255));"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Try
            cmd.ExecuteNonQuery()
        Catch ex As Exception
        End Try
        con.Close()



        SQLCommand = "CREATE TABLE Inventory(ProductID varchar(255) PRIMARY KEY, ProductName VarChar(255), ItemCost varchar(255)," &
            "ItemPrice varchar(255), ItemQuantity varchar(255), SupplierID varchar(255), FOREIGN KEY (SupplierID) REFERENCES Supplier(SupplierID))"


        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Try
            cmd.ExecuteNonQuery()
        Catch ex As Exception
        End Try
        con.Close()


        SQLCommand = "CREATE TABLE Orders(OrderID varchar(255) PRIMARY KEY, ProductID varchar(255), FOREIGN KEY (ProductID) REFERENCES Inventory(ProductID)," &
            "CustomerID varchar(255), FOREIGN KEY (CustomerID) REFERENCES Customer(CustomerID), DateofPurchase varchar(255), TimeofPurchase varchar(255))"


        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Try
            cmd.ExecuteNonQuery()
        Catch ex As Exception
        End Try
        con.Close()
    End Sub
End Class


Imports ADOX
Imports System.IO
Imports System.Data.OleDb


Public Class Suppliers
    Dim ConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
    Dim cat As Catalog = New Catalog()
    Dim SQLCommand As String
    Dim con As New OleDbConnection(ConnectionString)
    Dim cmd As New OleDbCommand
    Private Sub Suppliers_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    'When the add button is clicked, the supplier table is updated and the datagrid view is updated too.
    Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click

        AddSupplier()
        UpdatetableS()

    End Sub

    'This sub puts the table in the database into the datagridview
    Private Sub UpdatetableS()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("Select * from [Supplier]", MyConn)
        da.Fill(ds, "Supplier")
        Dim view As New DataView(tables(0))
        source1.DataSource = view
        DatagridviewSup.DataSource = view



    End Sub

    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        UpdatetableS()
    End Sub

    ' this sub allwows the user to go back to the main menu
    Private Sub btnCustback_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCustback.Click
        If Me.Visible() Then
            Me.Close()
            Main_Menu.Show()
        End If
    End Sub

    Private Sub SeachTable()

        Dim sqlsearch As String
        sqlsearch = "SELECT * FROM Supplier WHERE SupplierID = '" & SupID.Text & "'" & " OR BusinessName = '" & supbusinessname.Text & "'" & " OR ContactName = '" & SupContactName.Text & "'" & " OR BusinessEmail = '" & SupEmailAddress.Text & "'" & " OR BusinessAddress = '" & SupAddress.Text & "'" & " OR BusinessCity = '" & SupCity.Text & "'" & " OR BusinessPostcode = '" & SupPost.Text & "'"

        ' execute the SQL statements against the dataBase
        Dim adapter As New OleDbDataAdapter(sqlsearch, con)
        ' Shows the records and updates the DataGridView
        Dim dt As New DataTable("Supplier")
        adapter.Fill(dt)
        DatagridviewSup.DataSource = dt

    End Sub

    Private Sub btnsearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsearch.Click
        SeachTable()
    End Sub

    'This sub adds the information typed into the textboxes into a table in the database
    Private Sub AddSupplier()
        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand
        If SupID.Text = "" Or supbusinessname.Text = "" Or SupContactName.Text = "" Or SupEmailAddress.Text = "" Or SupAddress.Text = "" Or SupCity.Text = "" Or SupPost.Text = "" Then
            MsgBox("Please fill in all given fields!")

        Else

            con.Open()
            cmd.Connection = con

            cmd.CommandText = "INSERT INTO Supplier(SupplierID,BusinessName,ContactName,BusinessEmail,BusinessAddress,BusinessCity,BusinessPostcode) VALUES ('" & SupID.Text & "','" & supbusinessname.Text & "', '" & SupContactName.Text & "', '" & SupEmailAddress.Text & "','" & SupAddress.Text & "','" & SupCity.Text & "', '" & SupPost.Text & "')"
            SupID.Clear()
            supbusinessname.Clear()
            SupContactName.Clear()
            SupEmailAddress.Clear()
            SupAddress.Clear()
            SupCity.Clear()
            SupPost.Clear()

            cmd.ExecuteNonQuery()
            ' UpdateTable()
            con.Close()
        End If
    End Sub

End Class

Imports ADOX
Imports System.IO
Imports System.Data.OleDb

Public Class orders
    Public ConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
    Dim cat As Catalog = New Catalog()
    Dim SQLCommand As String
    Dim con As New OleDbConnection(ConnectionString)
    Dim cmd As New OleDbCommand
    Private Sub btnBack_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBack.Click
        If Me.Visible() Then
            Me.Close()
            Main_Menu.Show()
        End If
    End Sub

    Private Sub orders_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


    End Sub

    'This sub fills the combobox with information other tables.
    Private Sub FillComboProduct()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        'Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("SELECT ProductID from Inventory", MyConn)
        da.Fill(ds, "Inventory")
        Dim view As New DataView(tables(0))

        Try
            With cmbProduct

                .DataSource = ds.Tables("Inventory")
                .DisplayMember = "ProductID"
                .ValueMember = "productID"

                .SelectedIndex = 0
                .AutoCompleteMode = AutoCompleteMode.SuggestAppend
                .AutoCompleteSource = AutoCompleteSource.ListItems
            End With
        Catch ex As Exception
            MsgBox("No ProductID has been created")
        End Try

    End Sub
    Private Sub btnGetIDs_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetIDs.Click
        FillComboProduct()
        FillComboCustomer()
    End Sub

    Private Sub FillComboCustomer()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection

        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("SELECT CustomerID from Customer", MyConn)
        da.Fill(ds, "Customer")
        Dim view As New DataView(tables(0))

        Try
            With cmbCustomer

                .DataSource = ds.Tables("Customer")
                .DisplayMember = "CustomerID"
                .ValueMember = "CustomerID"

                .SelectedIndex = 0
                .AutoCompleteMode = AutoCompleteMode.SuggestAppend
                .AutoCompleteSource = AutoCompleteSource.ListItems
            End With
        Catch ex As Exception
            MsgBox("No CustomerID has been created")
        End Try
    End Sub


    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        UpdateOrders()
    End Sub

    Private Sub UpdateOrders()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("Select * from [Orders]", MyConn)
        da.Fill(ds, "Orders")
        Dim view As New DataView(tables(0))
        source1.DataSource = view
        DataGridView1.DataSource = view
    End Sub

    Private Sub AddOrder()
        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand
        If txtOrderID.Text = "" Or txtDateOfP.Text = "" Or cmbCustomer.Text = "" Or cmbProduct.Text = "" Then
            MsgBox("Please fill in all given fields!")

        Else

            con.Open()
            cmd.Connection = con

            cmd.CommandText = "INSERT INTO Orders(OrderID,ProductID,CustomerID,DateofPurchase,TimeofPurchase) VALUES ('" & txtOrderID.Text & "','" & cmbProduct.Text & "','" & cmbCustomer.Text & "', '" & txtDateOfP.Text & "','" & txtTimeOfP.Text & "')"


            cmd.ExecuteNonQuery()
            ' UpdateTable()
            con.Close()
        End If
    End Sub

    Private Sub btnAddOrder_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddOrder.Click
        AddOrder()
        UpdateOrders()
    End Sub
    'This sub allows the user to search through the table and dispays the result
    Private Sub SearchTable()
        Dim sqlsearch As String
        sqlsearch = "SELECT * FROM Order WHERE OrderID = '" & txtOrderID.Text & "'" & " OR ProductID = '" & cmbProduct.Text & "'" & " OR CustomerID = '" & cmbCustomer.Text & "');" & " OR DateofPurchase = '" & txtDateOfP.Text & "'" & " OR TimeofPurchase = '" & txtTimeOfP.Text & "'"

        ' execute the SQL statements against the dataBase
        Dim adapter As New OleDbDataAdapter(sqlsearch, con)
        ' Shows the records and updates the DataGridView
        Dim dt As New DataTable("Order")
        adapter.Fill(dt)
        DataGridView1.DataSource = dt
    End Sub

    Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click
        SearchTable()
    End Sub

    Private Sub TimeDate()
        txtTimeOfP.Text = Now.ToShortDateString
        txtDateOfP.Text = Now.ToShortTimeString

    End Sub

    Private Sub txtDateOfP_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtDateOfP.TextChanged

    End Sub

    Private Sub TimenDate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimenDate.Click
        TimeDate()
    End Sub
    'Grade B (writing to a file)
    Private Sub PrintToFile()

        ' This goes through the rows and columns of the datagridview and then turns into string and tthen adds it the text file.
        Dim file As TextWriter = New StreamWriter("N:\Orders.txt")

        For i As Integer = 0 To DataGridView1.Rows.Count - 2 Step +1

            For j As Integer = 0 To DataGridView1.Columns.Count - 1 Step +1

                file.Write(vbTab & DataGridView1.Rows(i).Cells(j).Value.ToString() & vbTab & "|")

            Next

            file.WriteLine("")
            file.WriteLine("-----------------------------------------------------------------------------------------------------------")

        Next
        file.Close()
        MessageBox.Show("Data Exported")

    End Sub
    ' This sub checks whether the datagrid is empty and if it is, it will tell the user.
    Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrint.Click
        If DataGridView1.Rows.Count > 0 Then
            PrintToFile()
        Else
            MsgBox("Please fill/update the table to continue.")


        End If


    End Sub
End Class

Imports ADOX
Imports System.IO
Imports System.Data.OleDb



Public Class Customer
    Dim ConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
    Dim cat As Catalog = New Catalog()
    Dim SQLCommand As String
    Dim con As New OleDbConnection(ConnectionString)
    Dim cmd As New OleDbCommand
    Private Sub Customer_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub


    Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        Addrow()
        UpdateTable()
    End Sub


    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        UpdateTable()
    End Sub
    'This sub gets the latest version of the table from te database and puts it into the datagrid view. It selects every column from the table.
    Private Sub UpdateTable()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("Select * from [Customer]", MyConn)
        da.Fill(ds, "Customer")
        Dim view As New DataView(tables(0))
        source1.DataSource = view
        custdatagrid.DataSource = view

    End Sub

    Private Sub SearchTable()

        'SQL Statement so our User can search for either CustomerID or FirstName
        Dim sqlsearch As String
        sqlsearch = "SELECT * FROM Customer WHERE CustomerID = '" & CustID.Text & "'" & " OR FirstName = '" & CustFirstName.Text & "'" & " OR LastName = '" & CustSecondName.Text & "'" & " OR Email = '" & CustEmailAddress.Text & "'" & " OR LastName = '" & CustSecondName.Text & "'" & " OR Address = '" & CustHomeAddress.Text & "'" & " OR City = '" & CustCity.Text & "'" & " OR Postcode = '" & CustPost.Text & "'"

        ' execute the SQL statements against the dataBase
        Dim adapter As New OleDbDataAdapter(sqlsearch, con)
        ' Shows the records and updates the DataGridView
        Dim dt As New DataTable("Customer")
        adapter.Fill(dt)
        custdatagrid.DataSource = dt

    End Sub

    Private Sub btnsearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsearch.Click
        SearchTable()
    End Sub

    Private Sub btnCustback_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCustback.Click
        If Me.Visible() Then
            Me.Close()
            Main_Menu.Show()
        End If


    End Sub
    'This sub deletes the selected row from the datagrid view table and also deletes it from the table in the database.
    Private Sub DeleteRow()
        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand

        con.Open()
        cmd.Connection = con

        cmd.CommandText = "DELETE * from [Customer] where CustomerID = '" & custdatagrid.SelectedRows(0).Cells(0).Value.ToString() & "'"

        cmd.ExecuteNonQuery()
        UpdateTable()
        con.Close()


    End Sub

    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
        DeleteRow()
    End Sub

    Private Sub Addrow()
        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand
        If CustFirstName.Text = "" Or CustSecondName.Text = "" Or CustEmailAddress.Text = "" Or CustHomeAddress.Text = "" Or CustCity.Text = "" Or CustPostcode.Text = "" Then
            MsgBox("Please fill in all given fields!")

        Else

            con.Open()
            cmd.Connection = con

            cmd.CommandText = "INSERT INTO Customer(CustomerID,FirstName,LastName,Email,Address,City,Postcode) VALUES ('" & CustID.Text & "','" & CustFirstName.Text & "', '" & CustSecondName.Text & "', '" & CustEmailAddress.Text & "','" & CustHomeAddress.Text & "','" & CustCity.Text & "', '" & CustPost.Text & "')"
            CustID.Clear()
            CustFirstName.Clear()
            CustSecondName.Clear()
            CustEmailAddress.Clear()
            CustHomeAddress.Clear()
            CustCity.Clear()
            CustPost.Clear()

            cmd.ExecuteNonQuery()
            UpdateTable()
            con.Close()

        End If
    End Sub


    ' This puts all the firstnames into an array and sorts it.
    Public Sub SortName()

        Dim n As Integer = 0
        Dim i As Integer = -1
        Dim Reader As OleDbDataReader

        SQLCommand = "SELECT FirstName FROM Customer"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Reader = cmd.ExecuteReader

        Do While Reader.Read()
            i = i + 1
        Loop
        con.Close()

        Dim ArrayFirstname(i) As String
        SQLCommand = "SELECT FirstName FROM Customer"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = (SQLCommand)
        Reader = cmd.ExecuteReader

            Do While Reader.Read()
                ArrayFirstname = (Reader("FirstName"))
                n = n + 1
            Loop
            con.Close()

            MsgBox(ErrorToString)

            MergeSort(ArrayFirstname)

            For m = 0 To UBound(ArrayFirstname)
                custdatagrid.Rows.Item(m).Cells(i).Value = ArrayFirstname(m)
            Next

        For j = 0 To UBound(ArrayFirstname)

            SQLCommand = "SELECT CustomerID,LastName,Email,Address,City,Postcode FROM Customer WHERE FirstName = '" & ArrayFirstname(j) & "'"
            con.Open()
            cmd.Connection = con
            cmd.CommandText = (SQLCommand)
            Reader = cmd.ExecuteReader


            Do While Reader.Read()
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("CustomerID"))
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("LastName"))
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("Email"))
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("Address"))
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("City"))
                custdatagrid.Rows.Item(j).Cells(0).Value = (Reader("Postcode"))


            Loop

        Next

    End Sub



    'Grade A
    Public Sub MergeSort(ByRef data1 As String())

        Dim Csize As Integer
        Dim L As Integer

        Csize = 1
        While Csize <= data1.Length - 1
            L = 0
            While Left < data1.Length - 1
                Dim Mid As Integer = L + Csize - 1
                Dim Right As Integer = Math.Min(Left + 2 * Csize - 1, data1.Length - 1)

                Merge(data1, L, Mid, Right)
                L += 2 * Csize
            End While
            Csize = 2 * Csize
        End While



    End Sub

    Private Sub btnMergeSort_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMergeSort.Click
        SortName()
    End Sub

    ' Compares the items and outs them in order
    Private Sub Merge(ByRef data1 As String(), ByVal L As Integer, ByVal Mid As Integer, ByVal right As Integer)

        Dim i As Integer
        Dim j As Integer
        Dim k As Integer

        Dim Nom1 As String = Mid - L + 1
        Dim Nom2 As String = right - Mid

        Dim leftpointer As String() = New String(Nom1 - 1) {}
        Dim rightpointer As String() = New String(Nom2 - 1) {}

        For i = 0 To Nom1 - 1
            leftpointer(i) = data1(L - i)
        Next

        For j = 0 To Nom2 - 1
            rightpointer(j) = data1(Mid + 1 + j)
        Next


        i = 0
        j = 0
        k = L

        While i < Nom1 AndAlso j < Nom2

            If leftpointer(i) <= rightpointer(j) Then
                data1(k) = leftpointer(i)
                i += 1
            Else
                data1(k) = rightpointer(j)
                j += 1

            End If

            k += 1
        End While

        While i < Nom1
            data1(k) = leftpointer(i)
            i += 1
            k += 1
        End While

        While j < Nom2
            data1(k) = rightpointer(j)
            j += 1
            k += 1
        End While


    End Sub
End Class


Imports ADOX
Imports System.IO
Imports System.Data.OleDb

Public Class Inventory
    Dim ConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
    Dim cat As Catalog = New Catalog()
    Dim SQLCommand As String
    Dim con As New OleDbConnection(ConnectionString)
    Dim cmd As New OleDbCommand
    Private Sub Orders_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub btnCustback_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCustback.Click
        If Me.Visible Then
            Me.Hide()
            Main_Menu.Show()
        End If
    End Sub

    Private Sub ComboBoxsupplier_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBoxsupplier.SelectedIndexChanged

    End Sub

    Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        UpdateTable()
        AddInventory()

    End Sub

    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        UpdateTable()
    End Sub

    Private Sub UpdateTable()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("Select * from [Inventory]", MyConn)
        da.Fill(ds, "Inventory")
        Dim view As New DataView(tables(0))
        source1.DataSource = view
        Datagridview.DataSource = view

    End Sub

    Private Sub GetSupplierID_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles GetSupplierID.Click
        FillCombo()

    End Sub

    Private Sub btnCreate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub

    ' This sub fills the combo box/drop drop down
    Private Sub FillCombo()
        Dim ConnString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=N:\TestDatabase.accdb;"
        Dim MyConn As OleDbConnection
        Dim ds As DataSet
        Dim tables As DataTableCollection
        'Dim source1 As New BindingSource
        Dim da As OleDbDataAdapter

        MyConn = New OleDbConnection
        MyConn.ConnectionString = ConnString
        ds = New DataSet
        tables = ds.Tables

        da = New OleDbDataAdapter("SELECT SupplierID from Supplier", MyConn)
        da.Fill(ds, "Supplier")
        Dim view As New DataView(tables(0))

        Try
            With ComboBoxsupplier

                .DataSource = ds.Tables("Supplier")
                .DisplayMember = "SupplierID"
                .ValueMember = "SupplierID"

                .SelectedIndex = 0
                .AutoCompleteMode = AutoCompleteMode.SuggestAppend
                .AutoCompleteSource = AutoCompleteSource.ListItems
            End With
        Catch ex As Exception
            MsgBox("No SupplierID created")
        End Try

    End Sub

    Private Sub btnsearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsearch.Click
        searchtable()
    End Sub

    ' This sub searches for records in a table.
    Private Sub searchtable()
        Dim sqlsearch As String
        sqlsearch = "SELECT * FROM Inventory WHERE ProductID = '" & ItemID.Text & "'" & " OR ProductName = '" & ItemName.Text & "'" & " OR ItemPrice = '" & ProductPrice.Text & "'" & " OR ItemCost = '" & ProductCost.Text & "'" & " OR ItemQuantity = '" & ProductQuantity.Text & "'"

        ' execute the SQL statements against the dataBase
        Dim adapter As New OleDbDataAdapter(sqlsearch, con)
        ' Shows the records and updates the DataGridView
        Dim dt As New DataTable("Inventory")
        adapter.Fill(dt)
        Datagridview.DataSource = dt
    End Sub
    ' This sub  adds data from the textbox into the table.
    Private Sub AddInventory()
        Dim con As New OleDbConnection(ConnectionString)
        Dim cmd As New OleDbCommand
        If ItemID.Text = "" Or ItemName.Text = "" Or ProductCost.Text = "" Or ProductPrice.Text = "" Or ProductQuantity.Text = "" Or ComboBoxsupplier.Text = "" Then
            MsgBox("Please fill in all given fields!")

        Else

            con.Open()
            cmd.Connection = con

            cmd.CommandText = "INSERT INTO Inventory(ProductID,ProductName,ItemCost,ItemPrice,ItemQuantity,SupplierID) VALUES ('" & ItemID.Text & "','" & ItemName.Text & "', '" & ProductCost.Text & "', '" & ProductPrice.Text & "','" & ProductQuantity.Text & "','" & ComboBoxsupplier.Text & "')"
            ItemID.Clear()
            ItemName.Clear()
            ProductCost.Clear()
            ProductPrice.Clear()
            ProductQuantity.Clear()


            cmd.ExecuteNonQuery()
            ' UpdateTable()
            con.Close()
        End If

    End Sub
End Class