我的代码无法从excel到ms访问表导入数据

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

Public Class Defult
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack() Then
            Dim cnn As New OleDbConnection("Provider = Microsoft.ACE.OLEDB.12.0;Data Source=" & Server.MapPath("~/App_data/Data_List.accdb"))
            Dim cmd As New OleDbCommand

            cnn.Open()
            cmd.Connection = cnn
            cmd.CommandType = Data.CommandType.Text
            cmd.CommandText = " select '[Select Table Name]' as TABLE_NAME from dual union all select TABLE_NAME from tabs where table_name like 'FACT%' or table_name='Employee'"

            Try
                Dim dr As OleDbDataReader = cmd.ExecuteReader

                ddList.DataSource = dr
                ddList.DataValueField = "TABLE_NAME"
                ddList.DataTextField = "TABLE_NAME"
                ddList.DataBind()

                dr.Close()
                cmd.Dispose()
                cnn.Close()


            Catch ex As Exception
                Response.Write(ex.Message)
            End Try
        End If
    End Sub

    Protected Sub btnCopy_Click(ByVal sender As Object, e As EventArgs) Handles btnCopy.Click
        Dim xlpath As String
        Dim usr As String = HttpContext.Current.User.Identity.Name
        xlpath = Server.MapPath("~/ExcelFile/") & EXCEL_PATH.FileName

        Try
            Kill(xlpath)
        Catch
        End Try
        EXCEL_PATH.PostedFile.SaveAs(xlpath)

        Dim strConn As String = "Provider = Microsoft.ACE.OLEDB.12.0 ; Data Source = " & xlpath & " ; Extended Properties = Excel 8.0 ;"
        Dim cnnEXCEL As OleDbConnection = New OleDbConnection(strConn)

        Dim cnn As New OleDbConnection("Provider = Microsoft.ACE.OLEDB.12.0;Data Source=" & Server.MapPath("~/App_data/Data_List.accdb"))
        Dim cmd As New OleDbCommand

        Dim sql As String
        Dim i As Integer
        Dim sql1 As String = ""

        Dim iRow As Integer
        iRow = 1

        Try
            cnnEXCEL.Open()
            If EXCEL_PATH.FileName = "Employee.xlsx" Then
                sql = "SELECT * FROM[Sheet1$]"
            Else
                sql = "SELECT * FROM [" & ddList.SelectedValue.ToString & "$]"
            End If

            Dim oleda As OleDbDataAdapter = New OleDbDataAdapter(sql, cnnEXCEL)
            Dim ds As DataSet = New DataSet()
            oleda.Fill(ds, "Data_list")

            cnn.Open()
            cmd.Connection = cnn
            cmd.CommandType = Data.CommandType.Text
            cmd.CommandText = " truncate table " & ddList.SelectedValue.ToString
            cmd.ExecuteNonQuery()

            For Each dr As DataRow In ds.Tables("Data_List").Rows
                sql = "insert into " & ddList.SelectedValue.ToString & "VALUES ("
                sql1 = ""
                For i = 0 To ds.Tables("tbl1").Columns.Count - 1
                    If InStr(dr(i).ToString, "/") > 0 Then
                        sql1 = sql1 + "'" + dr(i).ToString() + "',"
                    Else
                        sql1 = sql1 + "'" + dr(i).ToString() + "',"
                    End If
                    iRow += 1
                Next
                sql &= sql1.Substring(0, sql1.Length - 1) + ")"

                cmd.Connection = cnn
                cmd.CommandType = Data.CommandType.Text
                cmd.CommandText = sql
                cmd.ExecuteNonQuery()

            Next
            lbMessage.Text = "Table Name: " & ddList.SelectedValue.ToString & ", Has: " & ds.Tables("tbl1").Rows.Count.ToString & " Record(s)"

        Catch ex As Exception
            lbMessage.Text = "Error: Upload Fail!! " & CStr(iRow) & ", Please check values not allows null/exceed columns"
        Finally
            cnnEXCEL.Close()

        End Try


    End Sub
End Class

What I have tried:

<big><big></big>My code has not an error but can not be imported.</big><big></big>