SQLAlchemy Model Django like Save Method?

Question

I am using sqlalchemy for a project. However, I am more accustomed to Django's ORM.

I would like to know if, in the sqlachemy ORM, there is anything similar to a Django models' save() method that I can overrride to implement actions automatically upon a 'commit' / 'save.'

Answer 1

You can extend your models with some simple crud methods to achieve something similar to Django ORM / ActiveRecord:

# SQLAlchemy db_session setup omitted
...

Model = declarative_base(name='Model')
Model.query = db_session.query_property()

class CRUD():

     def save(self):
         if self.id == None:
             db_session.add(self)
         return db_session.commit()

      def destroy(self):
          db_session.delete(self)
          return db_session.commit()

class User(Model, CRUD):
    __tablename__ = 'users'
    id = db.Column(db.integer, primary_key=True)
    email = db.Column(db.String(120), unique=True)

    def __init__(self, email):
        self.email = email

You can then save or destroy the model as needed:

user = User('[email protected]')
user.save()

Answer 2

Probably, you are looking for ORM events.

Take a look at instance events and session events.

Answer 3

Good news for you!

I created package for that. It implements Active Record pattern for SQLAlchemy.

See https://github.com/absent1706/sqlalchemy-mixins#active-record

It also has many very useful features such as Django lookups that span relationship, declarative eager load and readable print for SQAlchemy.