TypeORM module setup in NestJS - Mini Project: Build & Apply

TypeORM Module Setup in NestJS

📖 Scenario: You are building a simple NestJS application that needs to connect to a PostgreSQL database using TypeORM. You will set up the TypeORM module step-by-step to prepare your app for database operations.

🎯 Goal: Set up the TypeORM module in a NestJS application with a PostgreSQL connection configuration.

📋 What You'll Learn

Create a configuration object with database connection details

Import TypeORM module with the configuration in the root module

Use TypeORMModule.forRoot() method with the config object

Ensure the configuration includes host, port, username, password, database, and entities

💡 Why This Matters

🌍 Real World

Setting up TypeORM in NestJS is a common first step when building backend applications that need to store and retrieve data from a database.

💼 Career

Understanding how to configure TypeORM with NestJS is essential for backend developers working with modern Node.js frameworks and relational databases.

1

Create the database configuration object

Create a constant called databaseConfig as an object with these exact properties and values: type: 'postgres', host: 'localhost', port: 5432, username: 'testuser', password: 'testpass', database: 'testdb'.

NestJS

# Your code here

Need a hint?

Think of this object as the address and keys to your database house.

2

Add entities array to the configuration

Add a property called entities to the databaseConfig object and set it to an empty array [].

NestJS

const databaseConfig = {
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'testuser',
  password: 'testpass',
  database: 'testdb',
  // Add entities property here
};

Need a hint?

The entities array tells TypeORM which classes represent your database tables.

3

Import TypeOrmModule and configure it in AppModule

In the AppModule file, import TypeOrmModule from '@nestjs/typeorm'. Then, inside the @Module decorator's imports array, add TypeOrmModule.forRoot(databaseConfig).

NestJS

const databaseConfig = {
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'testuser',
  password: 'testpass',
  database: 'testdb',
  entities: []
};

import { Module } from '@nestjs/common';
// Import TypeOrmModule here

@Module({
  imports: [
    // Add TypeOrmModule.forRoot here
  ]
})
export class AppModule {}

Need a hint?

This step connects your NestJS app to the database using the config you made.

4

Enable auto-loading of entities

Add the property autoLoadEntities: true to the databaseConfig object to let TypeORM automatically load entities registered by other modules.

NestJS

const databaseConfig = {
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'testuser',
  password: 'testpass',
  database: 'testdb',
  entities: [],
  // Add autoLoadEntities property here
};

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';

@Module({
  imports: [
    TypeOrmModule.forRoot(databaseConfig)
  ]
})
export class AppModule {}

Need a hint?

This option helps your app find entity classes automatically without listing them all.