CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3ruby-on-rails-4
Arun Satyarth
Arun Satyarth

Reputation: 454

Rails Activerecord query for joining multiple tables

Models

class AdminUser < ActiveRecord::Base
    has_many :users
end
class User < ActiveRecord::Base
    has_many :posts
end
class Post < ActiveRecord::Base
    has_many :comments
end

I want to get a list of all comments under every post created by every User under this AdminUser.

To get all comments under every post done by 1 user is easy. I would use something like

comments=Comment.joins(:post).where("posts.user_id= ?",userid.to_s )

But here I need to go one more level up. ie get comments from every post made by every user under 1 admin_user. I have never used more than one join before, so I am a bit confused.

If I could use Activerecord association inside strings it might look like

        comments=Comment.joins(:post).joins(:user).where("posts.user.admin_user.id=?",adminuser_id)

But I cannot use posts.user.admin_user

Upvotes: 2

Views: 2413

Answers (2)

Santanu
Santanu

Reputation: 960

It should be like

Comment.joins(post: :user)

Upvotes: 1

Athar
Athar

Reputation: 3268

how about we first fetch the ids of users which belongs to admin user and then used to them to pick the comments using your query.

user_ids = admin_user.users.pluck(:id)
comments=Comment.joins(:post).where("posts.user_id IN  (?)", user_ids )

I have assumed that your query you pasted in question will work.

Upvotes: 2

Related Questions