Visual Basic

Public Class Form1
    Dim myDA As OleDbDataAdapter
    Dim myDataSet As DataSet

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=|DataDirectory|\db1.mdb")
        Dim cmd As OleDbCommand = New OleDbCommand("SELECT * FROM Sheet1", con)
        con.Open()
        myDA = New OleDbDataAdapter(cmd)
        Dim builder As OleDbCommandBuilder = New OleDbCommandBuilder(myDA)
        myDataSet = New DataSet()
        myDA.Fill(myDataSet, "MyTable")
        DataGridView1.DataSource = myDataSet.Tables("MyTable").DefaultView
        con.Close()
        con = Nothing
    End Sub
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Validate()
        Me.myDA.Update(Me.myDataSet.Tables("MyTable"))
        Me.myDataSet.AcceptChanges()
    End Sub

    Private Sub DataGridView1_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=|DataDirectory|\db1.mdb")
        Dim cmd As OleDbCommand = New OleDbCommand("SELECT * FROM Query3", con)
        con.Open()
        myDA = New OleDbDataAdapter(cmd)
        Dim builder As OleDbCommandBuilder = New OleDbCommandBuilder(myDA)
        myDataSet = New DataSet()
        myDA.Fill(myDataSet, "MyTable")
        DataGridView1.DataSource = myDataSet.Tables("MyTable").DefaultView
        con.Close()
        con = Nothing
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If OpenFileDialog1.ShowDialog(Me) = DialogResult.OK Then
            Dim fi As New FileInfo(OpenFileDialog1.FileName)
            Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Text;Data Source=" & fi.DirectoryName
            Dim Con As New OleDbConnection(sConnectionString)
            Dim myDataSet As DataSet = New DataSet()
            Dim cmd As OleDbCommand = New OleDbCommand
            Con.Open()
            myDA = New OleDbDataAdapter(cmd)
            Dim objCmdSelect As New OleDbCommand("SELECT * FROM " & fi.Name, Con)
            Dim objAdapter1 As New OleDbDataAdapter
            myDA.SelectCommand = objCmdSelect
            myDA.Fill(myDataSet, "MyTable")
            DataGridView1.DataSource = myDataSet.Tables("MyTable").DefaultView
            Con.Close()
            Con = Nothing
        End If
    End Sub
   
End Class