🎓 Complete TypeORM Course with TypeScript & Node.js

From Beginner to Production-Ready Applications

A comprehensive, hands-on course that takes you from zero to hero with TypeORM, TypeScript, and Node.js. Build real-world applications with PostgreSQL.

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📋 Course Overview

Duration	~40-50 hours
Level	Beginner to Advanced
Prerequisites	Basic JavaScript knowledge
Database	PostgreSQL
Framework	Express.js (with NestJS bonus)

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🎯 What You'll Learn

By the end of this course, you will be able to:

• ✅ Understand ORMs and why TypeORM is a powerful choice
• ✅ Set up TypeORM with TypeScript and Node.js from scratch
• ✅ Design and implement database entities with decorators
• ✅ Master all relationship types (One-to-One, One-to-Many, Many-to-Many)
• ✅ Build production-ready REST APIs with Express
• ✅ Handle migrations like a pro
• ✅ Implement soft deletes, transactions, and caching
• ✅ Write testable database code
• ✅ Deploy applications with Docker
• ✅ Build a complete capstone project

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📚 Course Curriculum

Section 01: Introduction to ORMs and TypeORM

• What is an ORM?
• Why use TypeORM?
• TypeORM vs Raw SQL
• TypeORM Architecture Overview
• Active Record vs Data Mapper Pattern

Section 02: Project Setup and Configuration

• Installing Node.js and TypeScript
• Setting up PostgreSQL
• Creating a TypeORM project from scratch
• Understanding DataSource configuration
• Environment variables and configuration management
• TypeORM CLI setup

Section 03: Entities, Columns, and Decorators

• What are Entities?
• Column types and options
• Primary columns and generated values
• Special columns (CreateDateColumn, UpdateDateColumn, etc.)
• Column transformers
• Entity inheritance

Section 04: Repositories and Data Access Layer

• Understanding Repositories
• Repository methods (find, save, update, delete)
• Custom repositories
• Repository pattern best practices
• DataSource API vs Repository API

Section 05: CRUD APIs with Express

• Setting up Express with TypeORM
• Building RESTful endpoints
• Request validation
• Error handling
• Project: Building a complete CRUD API

Section 06: Migrations

• Why migrations matter
• Generating migrations
• Running and reverting migrations
• Migration best practices
• Migrations in production

Section 07: Relationships

• One-to-One relationships
• One-to-Many / Many-to-One relationships
• Many-to-Many relationships
• Self-referencing relationships
• Cascade operations
• Eager vs Lazy loading
• Relationship best practices

Section 08: QueryBuilder

• Introduction to QueryBuilder
• SELECT queries
• INSERT, UPDATE, DELETE with QueryBuilder
• Joins and subqueries
• Raw queries
• When to use QueryBuilder vs Repository

Section 09: Soft Deletes and Paranoid Tables

• What is soft delete?
• Implementing soft deletes
• Querying soft-deleted records
• Restoring deleted records
• Best practices

Section 10: Database Seeding

• Why seed data?
• Creating seed scripts
• Using factories for test data
• Seeding in different environments

Section 11: Transactions

• Understanding transactions
• Transaction isolation levels
• Implementing transactions in TypeORM
• Nested transactions
• Error handling in transactions

Section 12: Performance Tuning

• Database indexing
• Query optimization
• Relation loading strategies
• Caching with TypeORM
• Connection pooling
• Logging and debugging

Section 13: Advanced Topics

• Entity subscribers and event listeners
• Embeddable entities
• Custom repositories (advanced)
• DTO validation with class-validator
• Multi-database connections

Section 14: Testing Database Code

• Unit testing repositories
• Integration testing with test database
• Mocking TypeORM
• E2E testing strategies
• Test fixtures and factories

Section 15: Capstone Project - Employee Management System

• Project requirements
• Database design
• Implementation step-by-step
• Authentication and authorization
• Complete API documentation

Section 16: Deployment with Docker

• Dockerizing your application
• Docker Compose for development
• Environment configuration
• Production deployment checklist
• CI/CD considerations

Bonus Section: Comparisons and Advanced Patterns

• TypeORM vs Sequelize vs Prisma
• TypeORM v0.3+ syntax changes
• Multi-tenant architecture
• Migrations in CI/CD pipelines
• Repository vs DataSource APIs

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🗂️ Course Structure

typeorm-course/
├── README.md                          # This file
├── CHEATSHEET.md                      # Quick reference guide
├── section-01-introduction/           # Introduction to ORMs
├── section-02-setup/                  # Project setup
├── section-03-entities/               # Entities and decorators
├── section-04-repositories/           # Repository pattern
├── section-05-crud-express/           # CRUD with Express
├── section-06-migrations/             # Database migrations
├── section-07-relationships/          # All relationship types
├── section-08-querybuilder/           # QueryBuilder deep dive
├── section-09-soft-deletes/           # Soft delete pattern
├── section-10-seeding/                # Database seeding
├── section-11-transactions/           # Transaction management
├── section-12-performance/            # Performance optimization
├── section-13-advanced/               # Advanced topics
├── section-14-testing/                # Testing strategies
├── section-15-capstone/               # Final project
├── section-16-deployment/             # Docker deployment
├── bonus-section/                     # Comparisons and extras
└── examples/                          # Complete example applications
    ├── express-typeorm-blog-app/      # Express + TypeORM Blog (migrations, relationships, transactions)
    └── nestjs-typeorm-app/            # NestJS + TypeORM Blog

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🚀 Complete Example Applications

Express + TypeScript + TypeORM Blog App

A comprehensive blog application demonstrating all TypeORM fundamentals:

• Entities: Author, Post, Comment with relationships
• Migrations: Complete migration setup with up/down methods
• Transactions: Atomic operations for complex business logic
• Soft Deletes: Post entity with soft delete support
• Query Builder: Advanced queries in services

cd examples/express-typeorm-blog-app
npm install
cp .env.example .env
npm run migration:run
npm run dev

NestJS + TypeORM Blog App

The same blog application built with NestJS framework:

• Module-based architecture: Users, Posts, Comments modules
• Dependency Injection: Repository injection with @InjectRepository
• DTO Validation: Request validation with class-validator
• Best Practices: Production-ready NestJS patterns

cd examples/nestjs-typeorm-app
npm install
cp .env.example .env
npm run migration:run
npm run start:dev

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🛠️ Tech Stack

Technology	Version	Purpose
Node.js	18+	Runtime
TypeScript	5.x	Language
TypeORM	0.3.x	ORM
PostgreSQL	15+	Database
Express	4.x	Web Framework
Jest	29.x	Testing
Docker	Latest	Containerization

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🚀 Getting Started

Prerequisites

1. Node.js (v18 or higher)

   node --version

2. PostgreSQL (v15 or higher)

   psql --version

3. npm or yarn

   npm --version

Quick Start

# Clone or navigate to the course folder
cd typeorm-course

# Each section has its own project
cd section-02-setup/demo

# Install dependencies
npm install

# Set up environment variables
cp .env.example .env

# Run the project
npm run dev

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📖 How to Use This Course

1. Follow in order: Each section builds on the previous one
2. Type the code: Don't just copy-paste; type it out for better learning
3. Complete assignments: Each section has homework tasks
4. Build the capstone: Apply everything you've learned
5. Reference the cheatsheet: Use it as a quick lookup

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🎁 Bonus Materials

• 📋 TypeORM Cheatsheet
• 🔍 Common Mistakes Guide
• ✅ Production Checklist
• 🏗️ Architecture Diagrams
• 📚 Additional Resources

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📚 Official Resources

• TypeORM Documentation
• TypeORM GitHub
• TypeScript Documentation
• PostgreSQL Documentation
• Express Documentation

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👨‍💻 Author

This course is designed to be practical, hands-on, and production-focused. Every concept is explained with real-world examples and best practices.

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📄 License

This course material is provided for educational purposes.

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Happy Learning! 🚀