fastapi-sqlalchemy-ease 0.1.5

A reusable SQLAlchemy extension for FastAPI

fastapi-sqlalchemy-ease

fastapi-sqlalchemy-ease is a singleton-based SQLAlchemy extension for FastAPI. It provides a centralized interface for database initialization, model declaration, and session management, inspired by the simplicity of Flask-SQLAlchemy.

◽ Key Features

• Singleton Design: Ensures a single database instance across your entire FastAPI application.

• Consolidated API: Access all SQLAlchemy types (Integer, String, ForeignKey, etc.) directly from the db object.

• Auto-Cleanup: Includes a generator-based session handler designed for FastAPI's Depends to ensure sessions are always closed.

• Built-in Lifecycle Management: Simple methods for create_all() and drop_all().

◽ Installation

pip install fastapi-sqlalchemy-ease

◽ Usage Guide

1. Basic setup

Initialize your database instance in a centralized file (e.g. database.py).

from fastapi_sqlalchemy_ease import SQLAlchemy  

'''Create the singleton instance''' 
db = SQLAlchemy()  

'''Initialize with your URI'''  
DATABASE_URI = "sqlite:///./test.db"  

'''Use connect_args={"check_same_thread": False} for SQLite'''  
db.init_app(DATABASE_URI, connect_args={"check_same_thread": False})  

2. Defining Models

No need to import types from SQLAlchemy; use the db instance directly.

class User(db.Model):  
    __tablename__ = "users"  

    id = db.Column(db.Integer, primary_key=True)  
    username = db.Column(db.String, unique=True, nullable=False)  
    created_at = db.Column(db.DateTime)  

3. Creating Tables

You can trigger table creation easily.

db.create_all()  

3. Database Operations in Routes

Use db.Session with FastAPI's Depends to get a clean session for every request.

from fastapi import FastAPI, Depends  
from .. import db  

app = FastAPI()  

@app.get("/users")  
def read_users(session: Session = Depends(db.Session)):  
    users = session.query(User).all()  
    return users  

◽ Available Attributes

Your db instance provides easy access to standard SQLAlchemy types and constraints:

Category - Available Attributes

Data Types - String, Integer, Float, Boolean, Text, Date, DateTime, JSON, Numeric
Constraints - ForeignKey, UniqueConstraint, CheckConstraint, Index
ORM - relationship, Table, Column

◽ Error Handling

The library includes a DatabaseNotInitializedError. If you attempt to access db.Model, db.Session, or lifecycle methods before calling db.init_app(), a clear exception will be raised to help you debug quickly.

📄 License

Distributed under the MIT License.

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