excel 导入到access时

protected void Button1_Click(object sender, EventArgs e)
    {

        string file = "Sheet1";
        string conn = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source =" + Server.MapPath("excel.xls") + ";Extended Properties='Excel 8.0;HDR=NO;'";
        OleDbConnection thisconnection = new OleDbConnection(conn);
        thisconnection.Open();
        string Sql = "select * from [" + file + "$]";
        OleDbDataAdapter mycommand = new OleDbDataAdapter(Sql, thisconnection);
        System.Data.DataSet ds = new System.Data.DataSet();
        mycommand.Fill(ds, "[" + file + "$]");
        thisconnection.Close();

        //string conn1 = "User ID=sa;Data Source=127.0.0.1;Password=;Initial Catalog=Lecture;Provider=SQLOLEDB.1;";
        OleDbConnection thisconnection1 = new OleDbConnection(ConfigurationManager.AppSettings["strConn"].ToString() + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["dbPath"]));
        thisconnection1.Open();
        int count =