Flask-SQLAlchemy Comprehensive Guide Repository

This repository provides a structured and detailed guide on using Flask-SQLAlchemy to manage models and interact with databases in Flask applications. The goal is to share knowledge about different attributes, column options, and best practices.

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Project Structure

flask-sqlalchemy-guide/
├── README.md                # Project overview and introduction
├── setup/                    # Environment setup instructions
│   └── environment.md
├── models/                   # Guides on defining models
│   ├── basic-models.md       # Basic model creation
│   ├── column-attributes.md  # Column options and attributes
│   ├── relationships.md      # Defining relationships (One-to-Many, Many-to-Many)
│   └── validations.md        # Model constraints and validation
├── database/                 # Database creation and management
│   ├── creating-tables.md    # How to create tables
│   └── migrations.md         # Database migrations with Flask-Migrate
└── examples/                 # Practical examples and best practices
    ├── simple-app/           # Simple Flask app with SQLAlchemy
    └── advanced-features/    # Advanced configurations

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1. Setting Up the Environment

setup/environment.md

Instructions to set up the environment:

• Installing Flask-SQLAlchemy
• Creating a virtual environment
• Connecting to different databases

Example Configuration:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///database.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db = SQLAlchemy(app)

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2. Defining Models

models/basic-models.md

Basic structure of defining models and mapping them to tables.

Example:

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)

models/column-attributes.md

Comprehensive list of column attributes:

• Data Types: db.Integer, db.String, db.Float, db.Boolean, etc.
• Common Options:
  • primary_key=True
  • nullable=False
  • unique=True
  • default=value

Example:

price = db.Column(db.Float, default=0.0, nullable=False)
created_at = db.Column(db.DateTime, default=db.func.now())

models/relationships.md

Guide on creating relationships between tables:

• One-to-Many
• Many-to-Many

Example:

class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    user = db.relationship('User', backref='posts')

models/validations.md

How to apply model-level constraints and validation.

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3. Database Management

database/creating-tables.md

Steps to create tables and manage the database lifecycle.

Creating Tables:

with app.app_context():
    db.create_all()

database/migrations.md

How to handle migrations using Flask-Migrate.

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4. Examples and Best Practices

examples/simple-app.md

A minimal example of a Flask app with a User model.

examples/advanced-features.md

Examples demonstrating advanced configurations such as:

• Custom Query Methods
• Database Indexing
• Performance Optimization

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How to Contribute

Feel free to open issues or submit pull requests to improve this guide.

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License

MIT License