Eve-SQLAlchemy extension

.. image:: https://travis-ci.org/pyeve/eve-sqlalchemy.svg?branch=master :target: https://travis-ci.org/pyeve/eve-sqlalchemy

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 <https://python-eve.org/>_ and SQLAlchemy <https://www.sqlalchemy.org/>_, it is recommended to read up on them first.

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

.. code-block:: python

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:

.. code-block:: python

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):

.. code-block:: python

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:

.. code-block:: console

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

.. code-block:: json

{
    "_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 <https://eve-sqlalchemy.readthedocs.org/>_. For full working examples, especially regarding different relationship types, see the examples directory in this repository.