Best Practice documentation for import (associations)

[chrisgo]

Awesome job getting to v5!

Possibly add a small example "best practice" of how to completely separate the model files in the documentation

http://docs.sequelizejs.com/manual/models-definition.html > Import

is very close but it does not address how to best put the associations into the separate model files

The examples here assume that you have imported all the models into this one file and then code all the associations after all the models have been imported

http://docs.sequelizejs.com/manual/associations.html

I believe most are using this an example prior to v5 https://codewithhugo.com/using-es6-classes-for-sequelize-4-models/

[trappar]

👍 This has me stumped too

[chrisgo]

There is an example here https://github.com/sequelize/express-example/blob/master/models/index.js

[brenc]

Also:

http://docs.sequelizejs.com/manual/models-definition.html > Import

const Project = sequelize.import(__dirname + "/path/to/models/project")

module.exports = (sequelize, DataTypes) => {
  class Project extends sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

This for me crashes with:

TypeError: Class extends value undefined is not a constructor or null

The sequelize instance doesn't appear to have a reference to Model. What works for me is this:

const Project = sequelize.import(__dirname + "/path/to/models/project")

// In the mode file:
const Sequelize = require('sequelize')

module.exports = (sequelize, DataTypes) => {
  class Project extends Sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

[jackie1120]

Also:

http://docs.sequelizejs.com/manual/models-definition.html > Import

const Project = sequelize.import(__dirname + "/path/to/models/project")

module.exports = (sequelize, DataTypes) => {
  class Project extends sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

This for me crashes with:

TypeError: Class extends value undefined is not a constructor or null

The sequelize instance doesn't appear to have a reference to Model. What works for me is this:

const Project = sequelize.import(__dirname + "/path/to/models/project")

// In the mode file:
const Sequelize = require('sequelize')

module.exports = (sequelize, DataTypes) => {
  class Project extends Sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

This for me crashes also,with: TypeError: Class extends value undefined is not a constructor or null. And i fix it with this method,is this a bug?

const Sequelize = require('sequelize')

module.exports = (sequelize, DataTypes) => {
  class Model extends Sequelize.Model {}
  Model.init({
    email: DataTypes.STRING,
    password: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'user'
  })
  return Model
}

[satheeshnatarajan]

const Sequelize = require('sequelize')

module.exports = (sequelize, DataTypes) => {
  class Model extends Sequelize.Model {}
  Model.init({
    email: DataTypes.STRING,
    password: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'user'
  })
  return Model
}

But associate not working while using import method

[papb]

Thanks for this issue. I was planning to do this for a while already... I really think this would help. I will try to get into this in a few days.

[ghost]

Any update? I have the same issue with TypeError: Class extends value undefined is not a constructor or null. Solution with additional const Sequelize = require('sequelize') in each module file looks for me like dirty hack :disappointed:

[papb]

@irekg I still plan on getting into this, unfortunately I am more busy than expected, hopefully you can wait a bit more :grimacing:

[ghost]

@papb I briefly looked at the code and it it looks like that all we need is another alias in /lib/sequelize.js.

// Aliases
Sequelize.prototype.fn = Sequelize.fn;
Sequelize.prototype.col = Sequelize.col;
Sequelize.prototype.cast = Sequelize.cast;
Sequelize.prototype.literal = Sequelize.literal;
Sequelize.prototype.and = Sequelize.and;
Sequelize.prototype.or = Sequelize.or;
Sequelize.prototype.json = Sequelize.json;
Sequelize.prototype.where = Sequelize.where;
Sequelize.prototype.validate = Sequelize.prototype.authenticate;
Sequelize.prototype.Model = Model; // <-- is it that simple or I'm missing something bigger?

It works fine for me with this alias. I can prepare PR if You like.

[papb]

@irekg Ah, okay, you are thinking of something much smaller than I was. If that single change helps you, I think it is super fine! Feel free to submit a PR.

[ghost]

Also:

http://docs.sequelizejs.com/manual/models-definition.html > Import

const Project = sequelize.import(__dirname + "/path/to/models/project")

module.exports = (sequelize, DataTypes) => {
  class Project extends sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

This for me crashes with:

TypeError: Class extends value undefined is not a constructor or null

The sequelize instance doesn't appear to have a reference to Model. What works for me is this:

const Project = sequelize.import(__dirname + "/path/to/models/project")

// In the mode file:
const Sequelize = require('sequelize')

module.exports = (sequelize, DataTypes) => {
  class Project extends Sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

@brenc Looking at the source code https://github.com/sequelize/sequelize/blob/d041e77e275c3e950cedcdb3a625d891ea8b056b/lib/sequelize.js#L1311

I noticed that it might be possible to do:

module.exports = (sequelize, DataTypes) => {
  class Project extends sequelize.Sequelize.Model { }
  Project.init({
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  }, { sequelize });
  return Project;
}

Haven't tried yet. I will test it tomorrow at work. IMHO If this works then it's the simplest workaround.

---

Update: tested. It works.

[papb]

@irekg Oh that's right!! So your PR wouldn't be needed after all...

[ghost]

@papb Right. But I think that example in documentation should be updated.

[papb]

Definitely. I will keep this open as a docs issue.