Skip to main content

SQLAlchemy integration with the marshmallow (de)serialization library

Project description

Latest version Build status Documentation marshmallow 3 compatible code style: black

Homepage: https://marshmallow-sqlalchemy.readthedocs.io/

SQLAlchemy integration with the marshmallow (de)serialization library.

Declare your models

import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session, sessionmaker, relationship, backref

engine = sa.create_engine("sqlite:///:memory:")
session = scoped_session(sessionmaker(bind=engine))
Base = declarative_base()


class Author(Base):
    __tablename__ = "authors"
    id = sa.Column(sa.Integer, primary_key=True)
    name = sa.Column(sa.String, nullable=False)

    def __repr__(self):
        return "<Author(name={self.name!r})>".format(self=self)


class Book(Base):
    __tablename__ = "books"
    id = sa.Column(sa.Integer, primary_key=True)
    title = sa.Column(sa.String)
    author_id = sa.Column(sa.Integer, sa.ForeignKey("authors.id"))
    author = relationship("Author", backref=backref("books"))


Base.metadata.create_all(engine)

Generate marshmallow schemas

from marshmallow_sqlalchemy import SQLAlchemySchema, auto_field


class AuthorSchema(SQLAlchemySchema):
    class Meta:
        model = Author
        load_instance = True  # Optional: deserialize to model instances

    id = auto_field()
    name = auto_field()
    books = auto_field()


class BookSchema(SQLAlchemySchema):
    class Meta:
        model = Book
        load_instance = True

    id = auto_field()
    title = auto_field()
    author_id = auto_field()

You can automatically generate fields for a model’s columns using SQLAlchemyAutoSchema. The following schema classes are equivalent to the above.

from marshmallow_sqlalchemy import SQLAlchemyAutoSchema


class AuthorSchema(SQLAlchemyAutoSchema):
    class Meta:
        model = Author
        include_relationships = True
        load_instance = True


class BookSchema(SQLAlchemyAutoSchema):
    class Meta:
        model = Book
        include_fk = True
        load_instance = True

Make sure to declare Models before instantiating Schemas. Otherwise sqlalchemy.orm.configure_mappers() will run too soon and fail.

(De)serialize your data

author = Author(name="Chuck Paluhniuk")
author_schema = AuthorSchema()
book = Book(title="Fight Club", author=author)
session.add(author)
session.add(book)
session.commit()

dump_data = author_schema.dump(author)
print(dump_data)
# {'id': 1, 'name': 'Chuck Paluhniuk', 'books': [1]}

load_data = author_schema.load(dump_data, session=session)
print(load_data)
# <Author(name='Chuck Paluhniuk')>

Get it now

pip install -U marshmallow-sqlalchemy

Requires Python >= 3.7, marshmallow >= 3.0.0, and SQLAlchemy >= 1.3.0.

Documentation

Documentation is available at https://marshmallow-sqlalchemy.readthedocs.io/ .

License

MIT licensed. See the bundled LICENSE file for more details.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

marshmallow-sqlalchemy-0.28.1.tar.gz (51.7 kB view hashes)

Uploaded Source

Built Distribution

marshmallow_sqlalchemy-0.28.1-py2.py3-none-any.whl (16.0 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page