text: from databases_lab import Base, Knowledge
  from sqlalchemy import create_engine
  from sqlalchemy.orm import sessionmaker
  
  engine = create_engine('sqlite:///knowledge.db')
  Base.metadata.create_all(engine)
  DBSession = sessionmaker(bind=engine)
  session = DBSession()
  
  
  
  def add_articles(topic_name,title,my_rating):
    	article_object = Knowledge(
          topic_name=topic_name,
          title=title,
          my_rating=my_rating)
          session.add(article_object)
          session.commit()
  
  
  #add_articles("brazil", "the wonders of south america", 4)
  # add_articles("soccer", "while is real madrid the greatest", 10)
  # add_articles("soccer", "while barcelone suck", 9)
  add_articles("h", "t", 8)
  add_articles("n", "k", 3)
  
  
  
  def query_all():
    k = session.query(
        Knowledge).all()
    return k
  
  
  def query_article_by_topic(topic_name):
    k= session.query(
      Knowledge).filter_by(
      topic_name=topic_name).all()
    return k
  
  
  def query_article_by_primary_key(topic_id):
    k= session.query(
      Knowledge).filter_by(
      topic_id=topic_id).all()
    return k
  
  
  def delete_article_by_topic(topic_name):
    session.query(Knowledge).filter_by(
      topic_name=topic_name).delete()
    session.commit()
  
  
  def delete_all_articles():
    session.query(Knowledge).delete()
    session.commit()
  
  
  def edit_rating(title,my_rating):
    article_object = session.query(
      Knowledge).filter_by(
      title=title).first()
    article_object.my_rating = my_rating
    session.commit()
  
  
  def delete_article_by_rating(rating1):
    session.query(Knowledge).filter(Knowledge.my_rating<=rating1).delete()
    session.commit()
  
  
  def top_5():
    k=session.query(
      Knowledge).order_by(
      Knowledge.my_rating).all()
    return k  
      
  
  
  print(top_5())  
  #print(query_article_by_primary_key(3))
  #(delete_article_by_topic("soccer"))
  #print(query_article_by_topic("soccer"))
  #delete_all_articles()
  #edit_rating("the wonders of south america", 9)
  #delete_article_by_rating(5)
  #print(query_all())
  
  
  
  
  
  
  
  
  
  
  
  