A friendly wrapper for SQLAlchemy.
SQLAlchemy is great, but can be difficult to set up. With SQLA-Wrapper you can quickly start like:
from sqla_wrapper import SQLAlchemy
db = SQLAlchemy('sqlite:///:memory:')
class User(db.Model):
__tablename__ "users"
id = db.Column(db.Integer, primary_key=True)
...
db.create_all()
todos = db.query(User.id, User.title).all()
instead of having to write something like:
# Who's going to remember all of this?
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, Column, Integer
engine = create_engine('sqlite:///:memory:')
Session = sessionmaker(bind=engine)
session = Session()
Model = declarative_base()
class User(Model):
__tablename__ "users"
id = Column(Integer, primary_key=True)
...
Model.metadata.create_all(engine)
session = Session()
todos = session.query(User).all()
Install the package using Pypi:
python -m pip install sqla-wrapper
from sqla_wrapper import SQLAlchemy
db = SQLAlchemy('sqlite:///:memory:')
class User(db.Model):
__tablename__ "users"
id = db.Column(db.Integer, primary_key=True)
...
db.create_all()
db.add(User(...))
db.commit()
todos = db.query(User).all()
Compared to plain SQLAlchemy, you need to know that:
The SQLAlchemy
gives you access to the following things:
- All the functions and classes from
sqlalchemy
andsqlalchemy.orm
- All the functions from a preconfigured scoped session (called
_session
). - The
~SQLAlchemy.metadata
and~SQLAlchemy.engine
- The methods
SQLAlchemy.create_all
andSQLAlchemy.drop_all
to create and drop tables according to the models. - A
Model
baseclass that is a configured declarative base. This model has a few utility methods:
class Model(Object):
@classmethod
def exists(cls, **attrs):
"""Returns whether an object with these attributes exists."""
@classmethod
def create(cls, **attrs):
"""Create and persist a new record for the model."""
@classmethod
def create_or_first(cls, **attrs):
"""Tries to create a new record, and if it fails
because already exists, return the first it founds."""
@classmethod
def first(cls, **attrs):
"""Returns the first object found with these attributes."""
def save(self):
"""Saves the updated model to the current entity db and commits."""
def delete(self):
"""Removes the model from the current session and commits."""
This model class also generates a default repr for your models, based on their class names an primary keys.