models.py

from sqlalchemy.orm import relationship
from sqlalchemy.dialects import postgresql
from flask_sqlalchemy import SQLAlchemy


def create_db(flask_instance):

    db = SQLAlchemy(flask_instance) 

    class Venue(db.Model):
        __tablename__ = 'venue'

        id = db.Column(db.Integer, primary_key=True)
        name = db.Column(db.String, nullable=False, unique=True)
        city = db.Column(db.String(50), nullable=False)
        state = db.Column(db.String(2), nullable=False)
        address = db.Column(db.String(120), nullable=False)
        phone = db.Column(db.String(15))
        image_link = db.Column(db.String(250))
        facebook_link = db.Column(db.String(250))
        seeking_talent = db.Column(db.Boolean, default=True)
        seeking_description = db.Column(db.String(100)) 
        genres = db.Column(postgresql.ARRAY(db.String, dimensions=1))
        
        def __repr__(self):
            return f"<Venue id={self.id}  name={self.name}>"
        
    artist_shows = db.Table("artist_shows", 
                            db.Column("show_id", db.ForeignKey("show.id"), primary_key=True),
                            db.Column("artist_id", db.ForeignKey("artist.id"), primary_key=True))

    venue_shows = db.Table("venue_shows",
                           db.Column("show_id", db.ForeignKey("show.id"), primary_key=True),
                           db.Column("venue_id", db.ForeignKey("venue.id"), primary_key=True))

    class Artist(db.Model):
        __tablename__ = 'artist'

        id = db.Column(db.Integer, primary_key=True)
        name = db.Column(db.String, unique=True, nullable=False)
        city = db.Column(db.String(50))
        state = db.Column(db.String(2))
        phone = db.Column(db.String(15))
        image_link = db.Column(db.String(250))
        facebook_link = db.Column(db.String(250))
        seeking_venue = db.Column(db.Boolean, default=True)
        seeking_description = db.Column(db.String(100))
        genres = db.Column(postgresql.ARRAY(db.String, dimensions=1))

        def __repr__(self):
            return f"<Artist id={self.id}  name={self.name}>"

    class Show(db.Model):
        __tablename__ = "show"

        id = db.Column(db.Integer, primary_key=True)
        start_time = db.Column(db.DateTime(), nullable=False)
        artist_id = relationship("Artist", 
                                 secondary=artist_shows, 
                                 backref=db.backref("shows", lazy=True),
                                 cascade="all, delete")
        
        venue_id = relationship("Venue",
                                secondary=venue_shows,
                                backref=db.backref("shows", lazy=True),
                                cascade="all, delete")

        def __repr__(self):
            return f"<Show id={self.id}  start_time={self.start_time}>"

    return db, Venue, Artist, Show