ticosax/graphene-sqlalchemy

Graphene SQLAlchemy integration

Please read UPGRADE-v2.0.md to learn how to upgrade to Graphene 2.0.

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Graphene-SQLAlchemy

A SQLAlchemy integration for Graphene.

Installation

For instaling graphene, just run this command in your shell

pip install "graphene-sqlalchemy>=2.0"

Examples

Here is a simple SQLAlchemy model:

from sqlalchemy import Column, Integer, String

from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class UserModel(Base):
    __tablename__ = 'user'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    last_name = Column(String)

To create a GraphQL schema for it you simply have to write the following:

import graphene
from graphene_sqlalchemy import SQLAlchemyObjectType

class User(SQLAlchemyObjectType):
    class Meta:
        model = UserModel
        # only return specified fields
        only_fields = ("name",)
        # exclude specified fields
        exclude_fields = ("last_name",)

class Query(graphene.ObjectType):
    users = graphene.List(User)

    def resolve_users(self, info):
        query = User.get_query(info)  # SQLAlchemy query
        return query.all()

schema = graphene.Schema(query=Query)

Then you can simply query the schema:

query = '''
    query {
      users {
        name,
        lastName
      }
    }
'''
result = schema.execute(query, context_value={'session': db_session})

You may also subclass SQLAlchemyObjectType by providing abstract = True in your subclasses Meta:

from graphene_sqlalchemy import SQLAlchemyObjectType

class ActiveSQLAlchemyObjectType(SQLAlchemyObjectType):
    class Meta:
        abstract = True

    @classmethod
    def get_node(cls, info, id):
        return cls.get_query(info).filter(
            and_(cls._meta.model.deleted_at==None,
                 cls._meta.model.id==id)
            ).first()

class User(ActiveSQLAlchemyObjectType):
    class Meta:
        model = UserModel

class Query(graphene.ObjectType):
    users = graphene.List(User)

    def resolve_users(self, info):
        query = User.get_query(info)  # SQLAlchemy query
        return query.all()

schema = graphene.Schema(query=Query)

Full Examples

To learn more check out the following examples:

• Flask SQLAlchemy example
• Nameko SQLAlchemy example

Contributing

Set up our development dependencies:

pip install -e ".[dev]"
pre-commit install  

We use tox to test this library against different versions of python and SQLAlchemy. While developping locally, it is usually fine to run the tests against the most recent versions:

tox -e py37  # Python 3.7, SQLAlchemy < 2.0
tox -e py37 -- -v -s  # Verbose output
tox -e py37 -- -k test_query  # Only test_query.py 

Our linters will run automatically when committing via git hooks but you can also run them manually:

tox -e pre-commit