VB.NET สอบถามเรื่องการดึงข้อมูลจากฐานข้อมูลมาใส่ dropdown ครับ มือใหม่หัดเขียน

Private Sub LoadRoomList()
        Try
            objConn = New SqlConnection(sysconfig)
            If (objConn.State = ConnectionState.Open) Then
                objConn.Close()
            End If
            objConn.Open()
            Dim sqlRoomName As String
            Dim dt As New DataTable
            sqlRoomName = "SELECT RoomID,RoomName,RoomLocation FROM MeetingRoom_V2 WHERE RoomStatus='A' AND RoomLV<='" & Session("mLV") & "'"
            objCmd = New SqlCommand(sqlRoomName, objConn)
            dtAdapter = New SqlDataAdapter(objCmd)
            dtAdapter.Fill(dt)
            If dt.Rows.Count > 0 Then
                ddlRoomSL.DataSource = dt
                ddlRoomSL.DataTextField = "RoomName"
                ddlRoomSL.DataValueField = "RoomID"
                ddlRoomSL.DataBind()
                ddlRoomSL.Items.Insert(0, "Please select room.")
            End If
        Catch ex As Exception
        Finally
            objConn.Close()
        End Try
    End Sub

ddlRoomSL.SelectedValue = dt.Rows(0)("RoomID")