text: from flask_philo.db.postgresql.orm import BaseModel
  
  from sqlalchemy import Column, ForeignKey, Integer, String
  from sqlalchemy.orm import relationship
  
  
  class Artist(BaseModel):
      __tablename__ = 'artist'
      name = Column(String(256))
      description = Column(String(256))
      albums = relationship('Album', backref='artist')
      genre_id = Column(Integer, ForeignKey('genre.id'))
  
  
  class Album(BaseModel):
      __tablename__ = 'album'
      name = Column(String(256))
      description = Column(String(256))
      artist_id = Column(Integer, ForeignKey('artist.id'))
  
  
  class Genre(BaseModel):
      __tablename__ = 'genre'
      name = Column(String(256))
      description = Column(String(256))
  