Excel importeren naar SQL Database met vb.net en asp.net

Ik post een antwoord, zodat als iemand anders dit tegenkomt, ze ook kunnen worden geholpen.

Hierdoor is alles voor mij gaan werken. (Shout out naar Kevin)

Protected Sub Button1_Click(sender As Object, e As System.EventArgs)
    Dim appPath As String = Request.PhysicalApplicationPath
        Dim con As New System.Data.SqlClient.SqlConnection
        con.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=" & appPath & "App_Data\Devicedatabase.MDF;Integrated Security=True;User Instance=True;"
        con.Open()
        MsgBox("open")
        con.Close()
        MsgBox("close")
    End Sub

Hierdoor kwam de verbinding open na veel proberen en frustratie.

Hierdoor zijn de Excel-waarden geïmporteerd in de database:

 Using con As New SqlClient.SqlConnection With
{
    .ConnectionString =
    "Data Source=.\SQLEXPRESS;AttachDbFilename=" & appPath & "App_Data\Devicedatabase.MDF;Integrated Security=True;User Instance=True;"
}
Using cmd As New SqlClient.SqlCommand With
    {
        .Connection = con,
        .CommandText = "INSERT INTO " & """" & DropDownList1.SelectedItem.ToString & """" & "ColumnName1, ColumnName2)VALUES (@Col1,@Col2)"
    }
    cmd.Parameters.Add(New SqlClient.SqlParameter With {.DbType = DbType.String, .ParameterName = "@Col1"})
    cmd.Parameters.Add(New SqlClient.SqlParameter With {.DbType = DbType.String, .ParameterName = "@Col2"})
    cmd.Parameters(0).Value = "Value obtained from Excel"
    cmd.Parameters(1).Value = "Value obtained from Excel"
    con.Open()
    Dim Result As Integer = cmd.ExecuteNonQuery
    If Result <> 1 Then
        MessageBox.Show("Insert failed.")
    Else
        MessageBox.Show("Row inserted.")
    End If

End Using
End Using

Geniet ervan jongens!