Eve-SQLAlchemy extension

Powered by Eve, SQLAlchemy and good intentions this extension allows to effortlessly build and deploy highly customizable, fully featured RESTful Web Services with SQL-based backends.

Eve-SQLAlchemy is simple

The following code blocks are excerpts of examples/one_to_many and should give you an idea of how Eve-SQLAlchemy is used. A complete working example can be found there. If you are not familiar with Eve and SQLAlchemy, it is recommended to read up on them first.

For this example, we declare two SQLAlchemy mappings (from domain.py):

class Parent(BaseModel):
    __tablename__ = 'parent'
    id = Column(Integer, primary_key=True)
    children = relationship("Child")

class Child(BaseModel):
    __tablename__ = 'child'
    id = Column(Integer, primary_key=True)
    parent_id = Column(Integer, ForeignKey('parent.id'))

As for Eve, a settings.py is used to configure our API. Eve-SQLAlchemy, having access to a lot of metadata from your models, can automatically generate a great deal of the DOMAIN dictionary for you:

DEBUG = True
SQLALCHEMY_DATABASE_URI = 'sqlite://'
SQLALCHEMY_TRACK_MODIFICATIONS = False
RESOURCE_METHODS = ['GET', 'POST']

DOMAIN = DomainConfig({
    'parents': ResourceConfig(Parent),
    'children': ResourceConfig(Child)
}).render()

Finally, running our application server is easy (from app.py):

app = Eve(validator=ValidatorSQL, data=SQL)

db = app.data.driver
Base.metadata.bind = db.engine
db.Model = Base

# create database schema on startup and populate some example data
db.create_all()
db.session.add_all([Parent(children=[Child() for k in range(n)])
                    for n in range(10)])
db.session.commit()

# using reloader will destroy the in-memory sqlite db
app.run(debug=True, use_reloader=False)

The API is now live, ready to be consumed:

$ curl -s http://localhost:5000/parents | python -m json.tool

{
    "_items": [
        {
            "_created": "Sun, 22 Oct 2017 07:58:28 GMT",
            "_etag": "f56d7cb013bf3d8449e11e8e1f0213f5efd0f07d",
            "_links": {
                "self": {
                    "href": "parents/1",
                    "title": "Parent"
                }
            },
            "_updated": "Sun, 22 Oct 2017 07:58:28 GMT",
            "children": [],
            "id": 1
        },
        {
            "_created": "Sun, 22 Oct 2017 07:58:28 GMT",
            "_etag": "dd1698161cb6beef04f564b2e18804d4a7c4330d",
            "_links": {
                "self": {
                    "href": "parents/2",
                    "title": "Parent"
                }
            },
            "_updated": "Sun, 22 Oct 2017 07:58:28 GMT",
            "children": [
                1
            ],
            "id": 2
        },
        "..."
    ],
    "_links": {
        "parent": {
            "href": "/",
            "title": "home"
        },
        "self": {
            "href": "parents",
            "title": "parents"
        }
    },
    "_meta": {
        "max_results": 25,
        "page": 1,
        "total": 10
    }
}

All you need to bring your API online is a database, a configuration file (defaults to settings.py) and a launch script. Overall, you will find that configuring and fine-tuning your API is a very simple process.

Eve-SQLAlchemy is thoroughly tested under Python 2.7-3.7 and PyPy.

Documentation

The offical project documentation can be accessed at eve-sqlalchemy.readthedocs.org. For full working examples, especially regarding different relationship types, see the examples directory in this repository.