Using SqlAlchemy Models in flask

Question

I created some models using SqlAlchemy for setting up the database initially. Initially i parse some XML files and populate the database. This is a one time thing which needs to be done when i setup the app on server.

Base = declarative_base()
class Movie(Base):
 __tablename__ = 'Movies'
 id = Column(Integer, primary_key=True, autoincrement=True)
 title = Column(String(80))
 filename = Column(String(80), unique=True)
 genre = Column(String(80))
 language = Column(String(80))
 year = Column(Integer)
 description = Column(Text)
 poster = Column(String)
 def __init__(self, title, filename, genre, language, year, description, poster):
 self.title = title
 self.filename = filename
 self.genre = genre
 self.language = language
 self.year = year
 self.description = description
 self.poster = poster
 def __repr__(self):
 return '<Movie (id=%d, title=%s, filename=%s, genre=%s, year=%s, description=%s, poster=%s)>' % (
 self.id, self.title, self.filename, self.genre, self.year, self.description, self.poster )
......

Now i want to use the same models in the flask also for a REST api. But from what i have seen, first i need to create a db instance using the flask app - like this

app = Flask(__name__)
db = SQLAlchemy(app)
class Movie(db.Model):
.......

How does this workout? Since my models are inheriting from the Base class but for flask they need to inherit from the db.Model class.

• nathancahill: Doesn't matter. The db.Model is just a proxy class for Base. You can do exactly what you have.
• Joe: Does this answer your question? Using SQLAlchemy models in and out of Flask
• Joe: I found a nice solution: stackoverflow.com/a/64668814/7919597

Answer 1

you can simply use your models as they are, they do not "need" to inherit from db.Model, that is simply a convince to make flask integration easier

• Magnus Lind Oxlund: It would be helpful to mention what specifically db.Model does that makes Flask integration easier.

Answer 2

You can to create a module with the SQLAlchemy instance and use only the inheritance in the another's modules.

in database.py module:

from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()

movieModel.py

from database import db
class MovieModel(db.Model):
 __tablename__ = 'movie'
 id = db.Column(db.Integer, primary_key=True)

imageModel.py

from database import db
class ImageModel(db.Model):
 __tablename__ = 'image'
 id = db.Column(db.Integer, primary_key=True)