How to set autoLoadEntities: true in connecting Nest js with typeorm

When using NestJS with TypeORM, setting autoLoadEntities: true simplifies the registration process of entities. This option enables automatic addition of all entities defined with the @Module decorator or imported within the module to the TypeORM database connection. Below are the specific steps to configure this option:

Step 1: Install Required Packages

First, ensure you have installed the necessary packages for NestJS and TypeORM. If not, install them using the following command:

bash
npm install @nestjs/typeorm typeorm

Step 2: Configure TypeORMModule

In your NestJS application, import TypeORMModule in the root module or any specific module. Here is an example of configuring autoLoadEntities: true in the root module:

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

@Module({
  imports: [
    TypeOrmModule.forRoot({
      type: 'postgres', // Select the database type, e.g., 'postgres', 'mysql', etc.
      host: 'localhost',
      port: 5432,
      username: 'your_username',
      password: 'your_password',
      database: 'your_database',
      autoLoadEntities: true, // Enable automatic entity loading
      synchronize: true, // Automatically create database tables based on entities; recommended only for development environments
    }),
  ],
})
export class AppModule {}

Step 3: Add Entities

Now, you can create entities in your application without explicitly adding each entity to the entities array. Simply mark the class with the @Entity() decorator, and TypeORM will automatically identify and load these entities. Here is an example of an entity:

typescript
import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;
}

Step 4: Verify Configuration

Start your NestJS application and verify the database to confirm that the corresponding tables are automatically created based on the entities. If autoLoadEntities is configured correctly, you should observe that the database tables corresponding to the entities have been created.

Summary

By setting autoLoadEntities: true, you can eliminate the need to manually register each entity, making database management more concise and efficient. This is particularly beneficial in large-scale projects, as manual management of entities becomes increasingly cumbersome with the growth of entity count.