Fetching specific details from mongo tracker store

Hello friend,Could you please tell me how are you fetching specific details from the tracker store. Elaborating my doubt below:

in my run_app.py (socketIO class) i have used mongotracker like this-

db = MongoTrackerStore(domain=“d.yml”,host=‘host ip’, db=‘xyz’, username=“x”,password=“x”,collection=“x”,event_broker=None)

agent = Agent.load(‘models/dialogue’, interpreter=‘models/current/nlu’,action_endpoint = action_endpoint,tracker_store=db)

now i want to fetch some data like db.sender_id or db.event. the reason of doing it is to store it column wise on my mongodb.Please help me solving this problem.