using morphMany or other ways of representing a many to many relationship

[ononotofu]

hi there ! i am trying to adapt the endpoints example to work with something similar to Books having many Tags but Tags not being unique to a specific book (because there might also be Magazines and other Books that share the Tag). would this always require joining with a through table? what if I also want to have Magazines associated with the same Tags collection -- would that require a second table to join?

https://gist.github.com/ononotofu/cb268fd3c5d8b37da376 has some related implementation. is a polymorphic association appropriate without a "Books_Tags" table -- and i'd prefer to not have many similarly named joining tables created to create the relationship. it seems like there is probably a best practice for something that comes up this often, but i can't find the same relationship mocked up in an example in either bookshelf or endpoints. appreciate any help!

[tenzan]

Hi! I'm not sure if this will be an answer to your question, but I did the following way to establish many-to-many relations, using posts and tags example, where posts_tags is a join table.

in posts/model.js

const instanceProps = {
  tableName: 'posts',
  hasTimestamps: true,
  tags: function () {
    return this.belongsToMany(require('../tags/model'), 'posts_tags');
  }

in tags/model.js:

const instanceProps = {
  tableName: 'tags',
  hasTimestamps: true,
  posts: function () {
    return this.belongsToMany(require('../posts/model'), 'posts_tags');
  }
};

My repo https://github.com/tenzan/node-api-pg and deployed at http://node-api-pg.herokuapp.com/

This app shares a db with another rails app at http://postag.herokuapp.com/