将listview项添加到sqlyog

Question

我在学校开设销售和库存系统。我想将listview项目保存到我的数据库，这是一个MySQL sqlyog终极。

这是我的连接以及用于将listview保存到数据库的代码但我收到错误Object variable or with block variable is not set。

Imports MySql.Data.MySqlClient

Module modconnector
    Public sqlcmd As New MySqlCommand
    Public sqlcon As New MySqlConnection
    Public sqladapter As New MySqlDataAdapter
    Public sqlreader As MySqlDataReader
    Public strsql As String

    Sub connect()
        sqlcon.ConnectionString = ("server=localhost;user id=root;password= ;database=sais")
        sqlcon.Open()
    End Sub



    Sub savelistview()

        sqlcon.Close()
        connect()


        iCount = ListView1.Items.Count()
        If Not ListView1.Items.Count = 0 Then
            Do Until iLoop = ListView1.Items.Count
                With lvitem
                    lvitem = ListView1.Items.Item(iLoop)

                    strsql = "insert into transaction(prod_code,prod_description,prod_price,order,quantity,date) values('" _
    & .Items(0).Text & "','" _
    & .SubItems(1).Text & "','" _
    & .SubItems(2).Text & "','" _
    & .SubItems(3).Text & "','" _
    & .SubItems(4).Text & "','" _
    & .SubItems(5).Text & "','" _
    & Label26.Text & "')"
                    sqlcmd.CommandText = strsql
                    sqlcmd.Connection = sqlcon
                    sqladapter.SelectCommand = sqlcmd
                    sqlcmd.ExecuteNonQuery()
                End With
                lvitem = Nothing
                iLoop = iLoop + 1

            Loop
        End If
        MessageBox.Show("Record Saved!")
        sqlcon.Close()
    End Sub
End Module