@mikro-orm/core

What is @mikro-orm/core?

@mikro-orm/core is an Object-Relational Mapper (ORM) for Node.js and TypeScript. It provides a powerful and flexible way to interact with databases using JavaScript/TypeScript objects. It supports multiple database drivers, including MySQL, PostgreSQL, SQLite, and MongoDB. The package offers features like entity management, query building, migrations, and more.

What are @mikro-orm/core's main functionalities?

Entity Management

Entity management allows you to define and manage your database entities using decorators. In this example, a `User` entity is defined with `id`, `name`, and `email` properties.

const { Entity, PrimaryKey, Property } = require('@mikro-orm/core');

@Entity()
class User {
  @PrimaryKey()
  id;

  @Property()
  name;

  @Property()
  email;
}

const user = new User();
user.name = 'John Doe';
user.email = '[e-mail]';

Query Building

Query building allows you to perform database operations using a fluent API. In this example, a query is built to find all users with the name 'John Doe'.

const { MikroORM } = require('@mikro-orm/core');

async function main() {
  const orm = await MikroORM.init({
    entities: [User],
    dbName: 'my-db-name',
    type: 'postgresql',
  });

  const userRepository = orm.em.getRepository(User);
  const users = await userRepository.find({ name: 'John Doe' });
  console.log(users);
}

main();

Migrations

Migrations allow you to manage database schema changes over time. In this example, a migration is created and then applied to the database.

const { MikroORM } = require('@mikro-orm/core');

async function main() {
  const orm = await MikroORM.init({
    entities: [User],
    dbName: 'my-db-name',
    type: 'postgresql',
  });

  const migrator = orm.getMigrator();
  await migrator.createMigration(); // creates file Migration20201019195930.ts
  await migrator.up(); // runs all pending migrations
}

main();

Other packages similar to @mikro-orm/core

typeorm

TypeORM is another ORM for TypeScript and JavaScript (ES7, ES6, ES5). It supports multiple databases like MySQL, PostgreSQL, MariaDB, SQLite, and more. TypeORM is known for its active community and extensive documentation. Compared to @mikro-orm/core, TypeORM offers a similar feature set but with a different API and some additional features like Active Record pattern support.

sequelize

Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite, and Microsoft SQL Server. It features solid transaction support, relations, eager and lazy loading, read replication, and more. Sequelize is widely used and has a large community. Compared to @mikro-orm/core, Sequelize is more mature and has broader database support but lacks some of the TypeScript-specific features.

objection

Objection.js is an ORM for Node.js that aims to stay as close to the relational database as possible. It is built on top of the SQL query builder Knex.js. Objection.js is known for its simplicity and flexibility. Compared to @mikro-orm/core, Objection.js provides a more lightweight and less opinionated approach to ORM, making it suitable for developers who prefer more control over their SQL queries.

README

The README file is missing