Graphene-SQLAlchemy

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)