Using Sequelize with Encore.ts

Encore.ts supports integrating Sequelize, a promise-based Node.js ORM. To set up Sequelize with Encore, start by creating a SQLDatabase instance and providing the connection string to Sequelize.

1. Setting Up the Database Connection

In database.ts, initialize the SQLDatabase and configure Sequelize:

// database.ts
import {
  Model,
  InferAttributes,
  InferCreationAttributes,
  CreationOptional,
  DataTypes,
  Sequelize,
} from "sequelize";
import { SQLDatabase } from "encore.dev/storage/sqldb";

// Create SQLDatabase instance with migrations configuration
const DB = new SQLDatabase("encore_sequelize_test", {
  migrations: "./migrations",
});

// Initialize Sequelize with the connection string
const sequelize = new Sequelize(DB.connectionString);

// Define the User model
class User extends Model<InferAttributes<User>, InferCreationAttributes<User>> {
  declare id: CreationOptional<number>;
  declare name: string;
  declare surname: string;
}

// Example usage: Count all users
const count = await User.count();

2. Creating Migrations

Encore does not currently support JavaScript migration files generated by tools like sequelize-cli model:generate. Instead, create and manage your own migration files in SQL format.

Example migration file for creating the user table:

-- migrations/1_create_user.up.sql --
CREATE TABLE "user" (
  id SERIAL PRIMARY KEY,
  name TEXT NOT NULL,
  surname TEXT NOT NULL
);

3. Applying Migrations

Migrations are automatically applied when you run your Encore application, so you don’t need to run sequelize db:migrate or similar commands manually.

For more information, see the example on GitHub:
<GitHubLink href="https://github.com/encoredev/examples/tree/main/ts/sequelize" desc="Using Sequelize ORM with Encore.ts" />