CODEWITHSUNDEEP
ruby-on-railspostgresqlruby-on-rails-4activerecord
Dan Benjamin
Dan Benjamin

Reputation: 900

rails query has_many through relationships

I have 4 classes: User, Platform and Listing and Item.

User has many platforms.

Platform has many items through listings.

Listing belongs to item and belongs to platform.

Item has many listings.

How would I go about getting all the users items?

My existing solution (which involves an in-efficient in-memory solution) is this:

user.platforms.includes(:items).inject([]) { |result, x| result + x.items }

Upvotes: 0

Views: 553

Answers (2)

szerlak
szerlak

Reputation: 76

You can use query started from Item and use user.id as parameter.

Item.joins(:platforms).where("platform.user_id = ?", user.id)

Upvotes: 0

szerlak
szerlak

Reputation: 76

You can add relation in your User model. ActiveRecord will take care about your query.

class User < ActiveRecord::Base
  has_many :platforms
  has_many :items, through: :platforms
end

Upvotes: 1

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