Connecting Microsoft Access Database with VisualBasic

Public Class Form1
    Dim con As New OleDb.OleDbConnection
    Dim dbProvider As String
    Dim dbSource As String
    Dim sql As String
    Dim da As OleDb.OleDbDataAdapter
    Dim listitem As ListViewItem

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        dbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;"
        dbSource = "Data Source = |DataDirectory|/Data.mdb;Persist Security Info=True"
        con.ConnectionString = dbProvider & dbSource

        Dim Header As ColumnHeader
        ListView1.Width = 405
        Header = New ColumnHeader
        Header.Text = "No"
        Header.TextAlign = HorizontalAlignment.Center
        Header.Width = 50
        ListView1.Columns.Add(Header)

        Header = New ColumnHeader
        Header.Text = "Name"
        Header.TextAlign = HorizontalAlignment.Center
        Header.Width = 150
        ListView1.Columns.Add(Header)

        Header = New ColumnHeader
        Header.Text = "City"
        Header.TextAlign = HorizontalAlignment.Center
        Header.Width = 100
        ListView1.Columns.Add(Header)

        Header = New ColumnHeader
        Header.Text = "Phone"
        Header.TextAlign = HorizontalAlignment.Center
        Header.Width = 100
        ListView1.Columns.Add(Header)
        Display()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text = "" Or TextBox2.Text = "" Or TextBox3.Text = "" Then
            MsgBox("Please Fill in the blank")
        Else
            con.Open()
            sql = "insert into Table1(PersonName,City,Phone) values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "')"
            Dim cmd As New OleDb.OleDbCommand(sql, con)
            cmd.CommandText = sql
            cmd.Connection = con
            cmd.ExecuteNonQuery()
            con.Close()
            Display()
            TextBox1.Text = ""
            TextBox2.Text = ""
            TextBox3.Text = ""
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If TextBox1.Text <> "" Then
            con.Open()
            sql = "update Table1 set City='" & TextBox2.Text & "',Phone='" & TextBox3.Text & "' where PersonName='" & TextBox1.Text & "'"
            Dim cmd As New OleDb.OleDbCommand(sql, con)
            cmd.CommandText = sql
            cmd.Connection = con
            cmd.ExecuteNonQuery()
            con.Close()
            Display()
            TextBox1.Text = ""
            TextBox2.Text = ""
            TextBox3.Text = ""
        Else
            MsgBox("Please Fill Name")
        End If
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If TextBox1.Text <> "" Then
            con.Open()
            sql = "delete from Table1 where PersonName='" & TextBox1.Text & "'"
            Dim cmd As New OleDb.OleDbCommand(sql, con)
            cmd.CommandText = sql
            cmd.Connection = con
            cmd.ExecuteNonQuery()
            con.Close()
            Display()
            TextBox1.Text = ""
            TextBox2.Text = ""
            TextBox3.Text = ""
        Else
            MsgBox("Please Fill Name")
        End If
    End Sub

    Private Sub Display()
        ListView1.Items.Clear()
        Dim MyTable As New DataTable
        con.Open()
        sql = "select *from Table1"
        da = New OleDb.OleDbDataAdapter(sql, con)
        da.Fill(MyTable)
        For i = 0 To MyTable.Rows.Count - 1
            listitem = ListView1.Items.Add((ListView1.Items.Count).ToString() + 1)
            listitem.SubItems.Add(MyTable.Rows(i)("PersonName"))
            listitem.SubItems.Add(MyTable.Rows(i)("City"))
            listitem.SubItems.Add(MyTable.Rows(i)("Phone"))
        Next
        con.Close()
    End Sub
End Class