old_contents: from ognskylines.dbutils import session
  from ognskylines.model import Device
  from ogn.utils import get_ddb, get_trackable
  
  
  from manager import Manager
  manager = Manager()
  
  
  @manager.command
  def import_ddb():
      """Import registered devices from the DDB (discards all devices before import)."""
      session.query(Device).delete()
  
      print("Import registered devices fom the DDB...")
      devices = get_trackable(get_ddb())
      for ogn_address in devices:
          device = Device(ogn_address=ogn_address[3:])
          session.add(device)
      session.commit()
      print("Imported {} devices.".format(len(devices)))
  
new_contents: from ognskylines.dbutils import session
  from ognskylines.model import Device
  import requests
  
  from manager import Manager
  manager = Manager()
  
  
  DDB_URL = "http://ddb.glidernet.org/download/?j=1"
  
  
  def get_ddb():
      devices = requests.get(DDB_URL).json()
      for device in devices['devices']:
          device.update({'identified': device['identified'] == 'Y',
                         'tracked': device['tracked'] == 'Y'})
          yield device
  
  
  @manager.command
  def import_ddb():
      """Import registered devices from the DDB (discards all devices before import)."""
      session.query(Device).delete()
  
      print("Import registered devices fom the DDB...")
      for device in get_ddb():
          if device['identified'] and device['tracked']:
              session.add(Device(ogn_address=device['device_id']))
  
      session.commit()
      print("Imported {} devices.".format(session.query(Device).count()))
  
subject: Add function to fetch devices from the DDB