MikroORM Setup

MikroORM is the alternative ORM in Ever Gauzy, providing stricter metadata validation, identity maps, and the Unit of Work pattern.

Configuration

Enabling MikroORM

# .env
DB_ORM=mikro-orm

Connection Options

MikroORM uses a similar database configuration to TypeORM:

MikroOrmModule.forRootAsync({
  useFactory: (configService: ConfigService) => ({
    type: configService.get("DB_TYPE"),
    host: configService.get("DB_HOST"),
    port: configService.get("DB_PORT"),
    dbName: configService.get("DB_NAME"),
    user: configService.get("DB_USER"),
    password: configService.get("DB_PASS"),
    entities: [...coreEntities, ...pluginEntities],
    discovery: { disableDynamicFileAccess: true },
    allowGlobalContext: true,
  }),
});

Key Differences from TypeORM

Feature	TypeORM	MikroORM
Pattern	Active Record + Data Mapper	Unit of Work
Change Tracking	Manual save	Automatic (Identity Map)
Metadata	Decorators at runtime	Stricter validation
Flushing	Immediate save()	Batch em.flush()
Relations	Eager/lazy optional	Reference wrappers
Entity Creation	repo.create()	em.create()

Repository Pattern

MikroORM Repositories

@Injectable()
export class MikroOrmEmployeeRepository extends MikroOrmBaseEntityRepository<Employee> {
  constructor(em: EntityManager) {
    super(em, Employee);
  }
}

Using the EntityManager

@Injectable()
export class EmployeeService {
  constructor(
    @InjectRepository(Employee)
    private readonly mikroOrmRepo: MikroOrmEmployeeRepository,
  ) {}

  async create(input: IEmployeeCreateInput): Promise<Employee> {
    const employee = this.mikroOrmRepo.create(input);
    await this.mikroOrmRepo.persistAndFlush(employee);
    return employee;
  }

  async findAll(): Promise<Employee[]> {
    return this.mikroOrmRepo.find(
      { isActive: true },
      { populate: ["user", "organization"] },
    );
  }
}

Unit of Work

MikroORM tracks entity changes automatically via the EntityManager's Identity Map:

// Load entity
const employee = await em.findOne(Employee, id);

// Modify in memory
employee.firstName = "Updated";

// Flush persists all changes in a single transaction
await em.flush();

Stricter Metadata

MikroORM validates entity metadata more strictly than TypeORM:

• All relation properties must have proper type hints
• Unique constraint definitions must reference property names (not column names)
• Entity discovery validates all decorators at startup

remarque

This strictness catches many common bugs at startup rather than at runtime, making MikroORM a good choice for production environments.

Known Considerations

Conditional Decorator Application

Since Gauzy supports both ORMs, Multi-ORM decorators are conditionally applied based on the active ORM:

// Only the MikroORM decorators are applied when DB_ORM=mikro-orm
// Only TypeORM decorators are applied when DB_ORM=typeorm

This prevents metadata conflicts. See Custom Entity Fields Registration Issues for more details on this pattern.

PostgreSQL vs SQLite Behavior

MikroORM's metadata validation is stricter with PostgreSQL than SQLite:

• PostgreSQL driver enforces all metadata constraints
• SQLite may silently ignore some constraints
• Always test with PostgreSQL for production deployments

Related Pages

• Database Overview — general database info
• TypeORM Setup — primary ORM
• Multi-ORM Architecture — Multi-ORM details
• Multi-ORM Entities — entity patterns