README.rst

sqlservice

The missing SQLAlchemy ORM interface.

Links

• Project: https://github.com/dgilland/sqlservice
• Documentation: http://sqlservice.readthedocs.io
• PyPI: https://pypi.python.org/pypi/sqlservice/
• Github Actions: https://github.com/dgilland/sqlservice/actions

Introduction

So what exactly is sqlservice and what does "the missing SQLAlchemy ORM interface" even mean? SQLAlchemy is a fantastic library and features a superb ORM layer. However, one thing SQLAlchemy lacks is a unified interface for easily interacting with your database through your ORM models. This is where sqlservice comes in. It's interface layer on top of SQLAlchemy's session manager and ORM layer that provides a single point to manage your database connection/session, create/reflect/drop your database objects, and easily persist/destroy model objects.

Features

This library is meant to enhance your usage of SQLAlchemy. SQLAlchemy is great and this library tries to build upon that by providing useful abstractions on top of it.

• Sync and asyncio database clients to manage ORM sessions with enhanced session classes.
• Base class for a declarative ORM Model that makes updating model columns and relationships easier and converting to a dictionary a breeze.
• Decorator-based event register for SQLAlchemy ORM events that can be used at the model class level. No need to register the event handler outside of the class definition.
• And more!

Requirements

• Python >= 3.7
• SQLAlchemy >= 2.0

Quickstart

First, install using pip:

pip install sqlservice

Then, define some ORM models:

import re
import typing as t

from sqlalchemy import ForeignKey, orm, types
from sqlalchemy.orm import Mapped, mapped_column

from sqlservice import declarative_base, event


Model = declarative_base()

class User(Model):
    __tablename__ = "user"

    id: Mapped[int] = mapped_column(types.Integer(), primary_key=True)
    name: Mapped[t.Optional[str]] = mapped_column(types.String(100))
    email: Mapped[t.Optional[str]] = mapped_column(types.String(100))
    phone: Mapped[t.Optional[str]] = mapped_column(types.String(10))

    roles: Mapped[t.List["UserRole"]] = orm.relationshipship("UserRole")

    @event.on_set("phone", retval=True)
    def on_set_phone(self, value):
        # Strip non-numeric characters from phone number.
        return re.sub("[^0-9]", "", value)


class UserRole(Model):
    __tablename__ = "user_role"

    id: Mapped[int] = mapped_column(types.Integer(), primary_key=True)
    user_id: Mapped[int] = mapped_column(types.Integer(), ForeignKey("user.id"), nullable=False)
    role: Mapped[str] = mapped_column(types.String(25), nullable=False)

Next, configure the database client:

from sqlservice import AsyncDatabase, Database

db = Database(
    "sqlite:///db.sql",
    model_class=Model,
    isolation_level="SERIALIZABLE",
    echo=True,
    echo_pool=False,
    pool_size=5,
    pool_timeout=30,
    pool_recycle=3600,
    max_overflow=10,
    autoflush=True,
)

# Same options as above are supported but will default to compatibility with SQLAlchemy asyncio mode.
async_db = AsyncDatabase("sqlite:///db.sql", model_class=Model)

Prepare the database by creating all tables:

db.create_all()
await async_db.create_all()

Finally (whew!), start interacting with the database.

Insert a new record in the database:

user = User(name='Jenny', email=jenny@example.com, phone='555-867-5309')
with db.begin() as session:
    session.save(user)

async with db.begin() as session:
    await session.save(user)

Fetch records:

session = db.session()
assert user is session.get(User, user.id)
assert user is session.first(User.select())
assert user is session.all(User.select().where(User.id == user.id)[0]

Serialize to a dict:

assert user.to_dict() == {
    "id": 1,
    "name": "Jenny",
    "email": "[email protected]",
    "phone": "5558675309"
}

assert dict(user) == user.to_dict()

Update the record and save:

user.phone = '222-867-5309'
with db.begin() as session:
    session.save(user)

async with async_db.begin() as session:
    await session.save(user)

Upsert on primary key automatically:

other_user = User(id=1, name="Jenny", email="[email protected]", phone="5558675309")
with db.begin() as session:
    session.save(other_user)
assert user is other_user

For more details, please see the full documentation at http://sqlservice.readthedocs.io.