text: ''' SQLAlchemy'''
  from flask_sqlalchemy import SQLAlchemy
  
  db = SQLAlchemy()
  
  class User(db.Model):
      '''Twitter Users'''
      id = db.Column(db.BigInteger, primary_key=True)
      name = db.Column(db.String(15), nullable=False)
      # Tweet IDs are odrdinal ints, so can be used to fetch only more recent
      newest_tweet_id = db.Column(db.BigInteger)
      
      def __repr__(self):
          return '[User {}]'.format(self.name)
  
  class Tweet(db.Model):
      ''' Tweets and their embeddings from basilica.'''
      id = db.Column(db.BigInteger, primary_key=True)
      text = db.Column(db.Unicode(300)) # Allows for full tweet + link
      embedding = db.Column(db.PickleType, nullable=False)
      user_id = db.Column(db.BigInteger, db.ForeignKey('user.id'), 
                          nullable=False)
      user = db.relationship('User', backref=db.backref('tweets', 
      lazy=True))
  
      def __repr__(self):
          return '[Tweet {}]'.format(self.text)
  
  
  
  
      