CODEWITHSUNDEEP
ruby-on-railsrubymany-to-manyhas-many-through
Nabs
Nabs

Reputation: 382

Rails many to many API query

Situation

I have 3 models as the following

class House < ApplicationRecord
  has_many :ownerships
  has_many :people, through: :ownerships
end

class Person < ApplicationRecord
  has_many :ownerships
  has_many :houses, through: :ownerships
end

and 

class Ownership < ApplicationRecord
  belongs_to :house
  belongs_to :person
end

Expected result

Basically, I'd like to make a query as JSON to get a list of all houses with associated people. The point is some houses don't have any people and some people don't own a house so the Ownership association doesn't have all the houses' ids. If a house doesn't belong to any person so the response should be nil.

The result from the query is, for example, the following:

{
  house1: {
    owners: [
      person1,
      person2
    ]
  },
  house2: {
    owners: null
  },
  house3: {
    owners: [
      person2
    ]
  }
}

What I've tried

I tried to use includes but I got separated arrays of items without the associated structure.

House.all.includes(:people).as_json(include: [:people])

but people value is in a separated key and not associated with the houses.

Upvotes: 0

Views: 57

Answers (1)

widjajayd
widjajayd

Reputation: 6253

for query you can as below

House.includes(ownerships: :person).as_json(include: [:people])

this will return house with your expected result. inside your includes, you type the relations between house -> ownerships (plural) then from ownership -> person (singular since ownership belong to)

Upvotes: 2

Related Questions