Sequelize: how to import definitions from an existing database

Question

Am I required to handwrite the model definitions for Sequelize even if I'm working off of an existing database.

If it's not required, then how does one go about using Sequelize with an existing database?

I've already defined the database's schema in Doctrine, so I'd rather not have to write another set of model definitions again.

Answer 1

with Sequelize you have to define the structure of the model inside your code. Doing so, Sequelize assumes a specific database schema unless something is overwritten. So in short: No, sequelize cannot mirror the database.

Hope that helps :)

Answer 2

This project aims to create Sequelize models from existing schema https://github.com/sequelize/sequelize-auto

Sequelize-Auto

A tool to automatically generate models for SequelizeJS via the command line.

Install:

npm install -g sequelize-auto

Usage:

sequelize-auto -h <host> -d <database> -u <user> -x [password] -p [port]  --dialect [dialect] -c [/path/to/config] -o [/path/to/models]

Options:

  -h, --host      IP/Hostname for the database.                                      [required]
  -d, --database  Database name.                                                     [required]
  -u, --user      Username for database.                                             [required]
  -x, --pass      Password for database.
  -p, --port      Port number for database.
  -c, --config    JSON file for sending additional options to the Sequelize object.
  -o, --output    What directory to place the models.
  -e, --dialect   The dialect/engine that you're using: postgres, mysql, sqlite

Example

sequelize-auto -o "./models" -d sequelize_auto_test -h localhost -u daniel -p 5432 -x my_password -e postgres

Produces a file/files such as ./models/Users.js which looks like this:

/* jshint indent: 2 */

module.exports = function(sequelize, DataTypes) {
  return sequelize.define('Users', {
    username: {
      type: DataTypes.STRING,
      allowNull: true,
      defaultValue: null
    },
    touchedAt: {
      type: DataTypes.DATE,
      allowNull: true,
      defaultValue: null
    },
    aNumber: {
      type: DataTypes.INTEGER,
      allowNull: true,
      defaultValue: null
    },
    id: {
      type: DataTypes.INTEGER,
      primaryKey: true
    },
    createdAt: {
      type: DataTypes.DATE,
      allowNull: false,
      defaultValue: null
    },
    updatedAt: {
      type: DataTypes.DATE,
      allowNull: false,
      defaultValue: null
    }
  });
};

Which makes it easy for you to simply Sequelize.import it.