Using EntityRepository instead of EntityManager

More convenient way of fetching entities from database is by using EntityRepository, that carries the entity name so you do not have to pass it to every find and findOne calls:

Example:

const booksRepository = orm.em.getRepository(Book);

// with sorting, limit and offset parameters, populating author references
const books = await booksRepository.find({ author: '...' }, ['author'], { title: QueryOrder.DESC }, 2, 1);

// or with options object
const books = await booksRepository.find({ author: '...' }, {
  populate: ['author'],
  limit: 1,
  offset: 2,
  orderBy: { title: QueryOrder.DESC },
});

console.log(books); // Book[]

Custom Repository

Since v4, we need to make sure we are working with correctly typed EntityRepository to have access to driver specific methods (like createQueryBuilder()). Use the one exported from your driver package. :::

To use custom repository, just extend EntityRepository<T> class:

import { EntityRepository } from '@mikro-orm/mysql'; // or any other driver package

@Repository(Author)
export class CustomAuthorRepository extends EntityRepository<Author> {

  // your custom methods...
  public findAndUpdate(...) {
    // ...
  }

}

You can also omit the @Repository decorator and register your repository in @Entity decorator instead:

@Entity({ customRepository: () => CustomAuthorRepository })
export class Author {
  // ...
}

Note that we need to pass that repository reference inside a callback so we will not run into circular dependency issues when using entity references inside that repository.

Now you can access your custom repository via em.getRepository() method.

Inferring custom repository type

To have the em.getRepository() method return correctly typed custom repository instead of the generic EntityRepository<T>, we can use EntityRepositoryType symbol:

@Entity({ customRepository: () => AuthorRepository })
export class Author {

  [EntityRepositoryType]?: AuthorRepository;

}

const repo = em.getRepository(Author); // repo has type AuthorRepository

You can also register custom base repository (for all entities where you do not specify customRepository) globally, via MikroORM.init({ entityRepository: CustomBaseRepository }).

Note that you cannot use both @Repository(Author) on the repository and { customRepository: () => AuthorRepository } on the entity at the same time. This will cause a circular dependency and throws an error. Either one of options achieves the same goal.

For more examples, take a look at tests/EntityManager.mongo.test.ts or tests/EntityManager.mysql.test.ts.