text: from c_and_c import db
  
  
  company_briefing_table = db.Table('company_briefing_table',
      db.Column('briefing_id', db.Integer, db.ForeignKey('briefing.id'), primary_key=True),
      db.Column('user_id', db.Integer, db.ForeignKey('user.id'), primary_key=True),
  )
  
  
  class FavoriteTable(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      student_id = db.Column(db.Integer, db.ForeignKey('user.id'), unique=False)
      company_id = db.Column(db.Integer, db.ForeignKey('user.id'), unique=False)
  
  
  class UserCompanyTable(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      student_id = db.Column(db.Integer, db.ForeignKey('user.id'), unique=False)
      company_id = db.Column(db.Integer, db.ForeignKey('user.id'), unique=False)
      access_count = db.Column(db.Integer)
  
  
  class User(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      name = db.Column(db.String(80), nullable=False, unique=True)
      type = db.Column(db.Integer, nullable=False)
      topic = db.Column(db.String(1000), nullable=True, unique=False)
      history = db.relationship('History', backref='user', lazy=True)
  
  
  class History(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      body = db.Column(db.String(1000), nullable=False)
      user_id = db.Column(db.Integer, db.ForeignKey('user.id'), unique=False)
  
  
  class Briefing(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      description = db.Column(db.String(1000), nullable=False)
      participants = db.relationship('User', backref='briefings', secondary=company_briefing_table, lazy=True)
  
  
  class Lecture(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      description = db.Column(db.String(1000), nullable=False)
  
  
  def init():
      db.create_all()
  