objection

What is objection?

Objection.js is an ORM (Object-Relational Mapper) for Node.js, built on top of the SQL query builder Knex.js. It aims to provide a powerful and flexible way to interact with SQL databases using JavaScript, while maintaining a clean and intuitive API.

What are objection's main functionalities?

Model Definition

Defines a model class that maps to a database table. In this example, the `Person` class represents the `persons` table in the database.

const { Model } = require('objection');

class Person extends Model {
  static get tableName() {
    return 'persons';
  }
}

Querying

Performs a query to fetch all persons older than 30 years. Objection.js provides a fluent API for building SQL queries.

const people = await Person.query().where('age', '>', 30);

Relations

Defines relationships between models. In this example, a `Person` can have many `Animal` pets, establishing a one-to-many relationship.

class Person extends Model {
  static get tableName() {
    return 'persons';
  }

  static get relationMappings() {
    const Animal = require('./Animal');
    return {
      pets: {
        relation: Model.HasManyRelation,
        modelClass: Animal,
        join: {
          from: 'persons.id',
          to: 'animals.ownerId'
        }
      }
    };
  }
}

Eager Loading

Fetches related data in a single query. This example fetches persons along with their pets using eager loading.

const peopleWithPets = await Person.query().withGraphFetched('pets');

Validation

Defines a JSON schema for model validation. This example ensures that `firstName` and `lastName` are required fields and must be strings of a certain length.

class Person extends Model {
  static get jsonSchema() {
    return {
      type: 'object',
      required: ['firstName', 'lastName'],
      properties: {
        id: { type: 'integer' },
        firstName: { type: 'string', minLength: 1, maxLength: 255 },
        lastName: { type: 'string', minLength: 1, maxLength: 255 }
      }
    };
  }
}

Other packages similar to objection

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. Compared to Objection.js, Sequelize has a more extensive feature set but can be more complex to use.

typeorm

TypeORM is an ORM for TypeScript and JavaScript (ES7, ES6, ES5). It supports many database systems including MySQL, MariaDB, PostgreSQL, SQLite, and more. TypeORM is known for its strong TypeScript support and decorators, making it a good choice for TypeScript projects. It offers similar functionalities to Objection.js but with a different API style.

bookshelf

Bookshelf.js is a JavaScript ORM for Node.js, built on top of the Knex.js SQL query builder. It provides a simple and straightforward way to interact with SQL databases. Bookshelf.js is similar to Objection.js in that both are built on Knex.js, but Bookshelf.js has a more minimalistic approach.

README

Objection.js

Objection.js is an ORM for Node.js that aims to stay out of your way and make it as easy as possible to use the full power of SQL and the underlying database engine while keeping magic to a minimum.

Objection.js is built on an SQL query builder called knex. All databases supported by knex are supported by objection.js. SQLite3, Postgres and MySQL are thoroughly tested.

What objection.js gives you:

• An easy declarative way of defining models and relationships between them
• Simple and fun way to fetch, insert, update and delete objects using the full power of SQL
• Powerful mechanisms for eager loading, inserting and upserting object graphs
• A way to store complex documents as single rows
• Completely Promise based API
• Easy to use transactions
• Optional JSON schema validation

What objection.js doesn't give you:

• A custom query DSL. SQL is used as a query language. This doesn't mean you have to write SQL strings though. A query builder based on knex is used to build the SQL. However, if the query builder fails you for some reason, raw SQL strings can be easily written using the raw helper function.
• Automatic database schema creation and migration from model definitions. For simple things it is useful that the database schema is automatically generated from the model definitions, but usually just gets in your way when doing anything non-trivial. Objection.js leaves the schema related things to you. knex has a great migration tool that we recommend for this job. Check out the example project.

Shortcuts:

• Who uses objection.js
• API reference
• Example projects
• Changelog
• Contribution guide
• Plugins