Sequelize: Include model of through.attribute

3
votes

Is it possible to include a model for an attribute of a many-to-many relation via through?

Let's say I'm having the following Models:

User = sequelize.define('user', {/* attributes */});
Question = sequelize.define('question', {/* attributes */});
Answer = sequelize.define('answer', {/* attributes */});

/* Where */
Question.hasMany(Answer);
Answer.belongsTo(Question);

I'd like to save for every user which answer he gave to a question. So I added the following relation:

UserQuestionAnswerRel = sequelize.define('usersAnwers', {
  user: {/**/},
  question: {/**/},
  answer: {/**/}
});

User.hasMany(Question, { through: UserQuestionAnswerRel });

Now I'd like to query a user receiving all questions he answered and the answer he gave. But how does that work? Unfortunately this doesn't work:

User.findAll({
  include: {
    model: Question,
    through: { include: model.Answer }
  }
}).then /* */

Please note: All this Q&A stuff is just an example. It won't be possible for me to not use a through relation.

2
javascriptsequelize.js
interesting. sorry i have no answer as yet. but wonder if its similar to my question. stackoverflow.com/questions/38714624/… i essentually want to access the 'through' model and filter on records left out of an 'inner' join - JAG
Can you explain why you have to use a through? This should be pretty straight forward to do with Nested eager loading... - Will

2 Answers

5
votes

I'd like to query a user receiving all questions he answered and the answer he gave

You should use Nested eager loading. So for example, you query might be something like:

User.findAll({
  include: {
    model: UserQuestionAnswerRel,
    include: [
      { model: Question },
      { model: Answer }
    ]
  }
}).then...
1
votes

I think the way to look at this question is:

`User.hasMany(Question); //this gives every question a userId
 Question.belongsTo(User);
 User.hasMany(Answer); //this gives every answer a userId
 Answer.belongsTo(User);
 Question.hasMany(Answer); //this gives every answer a questionId
 Answer.beongsTo(Question);

`

So, a query to get a user receiving all questions he answered and the answer he gave would go like this:

 `User.findAll({
  where: {
     id: userId
   },
   include: [
    { model: Answer },
       include: [
       { model: Question }
       ]
     ]
    });

`

This query is selecting a user with a supplier ID (userId) from the users table, and including all answers belong to that user, and also including all questions belonging to each of the answers included.

Let me know when you try this