🚀 TypeORM TypeScript Example

A comprehensive TypeORM example project demonstrating modern TypeScript patterns, database operations, and the Repository pattern with SQLite.

✨ Features

• 🏗️ TypeORM Integration - Full ORM setup with entities, repositories, and data source configuration
• 📊 SQLite Database - Lightweight, file-based database perfect for learning and development
• 🔧 Repository Pattern - Clean architecture with custom repository implementation
• 🎯 CRUD Operations - Complete Create, Read, Update, Delete functionality
• 📄 TypeScript - Fully typed with modern ES6+ features
• 🔍 Pagination Support - Built-in pagination for large datasets
• ⚙️ Environment Configuration - Flexible setup with environment variables
• 🧪 Production Ready - Environment-aware configuration for different deployment stages
• 📝 User-Post Relations - One-to-many relation between users and posts, with full repository support

📋 Table of Contents

• Quick Start
• Project Structure
• Usage Examples
• API Reference
• Configuration
• Contributing

🚀 Quick Start

Prerequisites

• Node.js (v16 or higher)
• npm or yarn

Installation

1. Clone the repository

   git clone <your-repo-url>
   cd typescript_course

2. Install dependencies

   npm install

3. Run the application

   npm start

That's it! The application will:

• Initialize the SQLite database
• Create sample users and posts
• Demonstrate various database operations
• Display results in the console

📁 Project Structure

typescript_course/
├── src/
│   ├── entity/
│   │   ├── User.ts          # User entity definition
│   │   └── Post.ts          # Post entity definition
│   ├── repository/
│   │   ├── UserRepository.ts # Custom repository with CRUD operations for users
│   │   └── PostRepository.ts # Custom repository with CRUD operations for posts
│   ├── migrations/          # Database migrations (optional)
│   ├── data-source.ts       # TypeORM data source configuration
│   └── index.ts            # Main application entry point
├── database.sqlite         # SQLite database file (auto-generated)
├── package.json           # Dependencies and scripts
└── tsconfig.json         # TypeScript configuration

💡 Usage Examples

Creating Users and Posts

const userRepository = new UserRepository();
const postRepository = new PostRepository();

const newUser = await userRepository.create({
  name: "John Doe",
  email: "[email protected]"
});

const post1 = await postRepository.create({
  title: "First Post",
  content: "This is the first post.",
  user: newUser
});

const post2 = await postRepository.create({
  title: "Second Post",
  content: "This is the second post.",
  user: newUser
});

Querying Users and Posts

// Find all users with their posts
const usersWithPosts = await userRepository.findAll(true);

// Find user by email with posts
const user = await userRepository.findByEmail("[email protected]", true);

// Find all posts with their user
const postsWithUser = await postRepository.findAll(true);

// Find posts by user id
const posts = await postRepository.findByUserId(newUser.id);

Updating Users and Posts

const updatedUser = await userRepository.update(1, {
  name: "Jane Doe"
});

const updatedPost = await postRepository.update(1, {
  title: "Updated Title"
});

Deleting Users and Posts

const isUserDeleted = await userRepository.delete(1);
const isPostDeleted = await postRepository.delete(1);

🔧 API Reference

UserRepository Methods

Method	Description	Parameters	Returns
create(userData)	Create a new user	Partial<User>	Promise<User>
findAll(withPosts?)	Get all users, optionally with posts	boolean?	Promise<User[]>
findById(id, withPosts?)	Find user by ID, optionally with posts	number, boolean?	Promise<User | null>
findByEmail(email, withPosts?)	Find user by email, optionally with posts	string, boolean?	Promise<User | null>
update(id, userData)	Update user	number, Partial<User>	Promise<User | null>
delete(id)	Delete user	number	Promise<boolean>
existsByEmail(email)	Check if email exists	string	Promise<boolean>
findWithPagination(page, limit, withPosts?)	Get paginated users, optionally with posts	number, number, boolean?	Promise<{users: User[], total: number}>
loadPosts(userId)	Get posts for a user	number	Promise<Post[]>

PostRepository Methods

Method	Description	Parameters	Returns
create(postData)	Create a new post	Partial<Post>	Promise<Post>
findAll(withUser?)	Get all posts, optionally with user	boolean?	Promise<Post[]>
findById(id, withUser?)	Find post by ID, optionally with user	number, boolean?	Promise<Post | null>
update(id, postData)	Update post	number, Partial<Post>	Promise<Post | null>
delete(id)	Delete post	number	Promise<boolean>
findByUserId(userId, withUser?)	Get posts by user id, optionally with user	number, boolean?	Promise<Post[]>

User Entity

interface User {
  id: number;          // Auto-generated primary key
  name: string;        // User's full name
  email: string;       // Unique email address
  posts: Post[];       // User's posts
}

Post Entity

interface Post {
  id: number;          // Auto-generated primary key
  title: string;       // Post title
  content: string;     // Post content
  user: User;          // Author (User)
}

⚙️ Configuration

Environment Variables

Create a .env file in the root directory:

DB_SYNCHRONIZE=true  # Auto-sync database schema (disable in production)
NODE_ENV=development # Environment mode

Database Configuration

The project uses SQLite by default, but you can easily switch to other databases by modifying src/data-source.ts:

export const AppDataSource = new DataSource({
  type: "postgres", // or "mysql", "mariadb", etc.
  host: "localhost",
  port: 5432,
  username: "your_username",
  password: "your_password",
  database: "your_database",
  // ... rest of configuration
});

🧪 Scripts

npm start          # Compile TypeScript and run the application
npm run typeorm    # Run TypeORM CLI commands

🤝 Contributing

Contributions are welcome! Here are some ways you can contribute:

• 🐛 Report bugs - Found an issue? Let us know!
• 💡 Suggest features - Have ideas for improvements?
• 📖 Improve documentation - Help make the docs better
• 🔧 Submit pull requests - Fix bugs or add features

Development Setup

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Make your changes
4. Commit your changes: git commit -m 'Add amazing feature'
5. Push to the branch: git push origin feature/amazing-feature
6. Open a Pull Request

📚 Learn More

• TypeORM Documentation - Learn about TypeORM features and configuration
• TypeScript Handbook - Master TypeScript fundamentals
• SQLite Documentation - Understand SQLite database features

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🌟 Show Your Support

If this project helped you learn TypeORM and TypeScript, please consider giving it a ⭐!

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Happy Coding! 🎉

Built with ❤️ using TypeORM and TypeScript