CODEWITHSUNDEEP
ruby-on-railsactiverecord
user2884789
user2884789

Reputation: 533

Rails getting a user name of a comment using join

I have a User Model: 

id, name, email
has_many :microposts, dependent: :destroy
has_many :comments, dependent: :destroy

A Micropost Model: 

id, content, title
belongs_to :user
has_many :comments, dependent: :destroy

and a Comment Model: 

id, content, user_id, micropost_id
belongs_to :user
  belongs_to :micropost
  has_one :micropost
  has_one :user

I would like to access the User Name of each comment through a comment itself. For example, I can get the user's name through micropost with micropost.user.name which will give me the User name of the user associated with a particular micropost. In the same vain, I'd like something like comment.user.name or in sql terms 

select user.name from User as user join Comment as comment where user.id = comment.user_id and comment.id = 12;

When I try to run comment.user.name I get an error:

User Load (1.0ms)  SELECT  "users".* FROM "users" WHERE "users"."comment_id" = ? LIMIT 1  [[nil, 3]]
SQLite3::SQLException: no such column: users.comment_id: SELECT  "users".* FROM "users" WHERE "users"."comment_id" = ? LIMIT 1

I see the problem with the SQL is there is no users.comment_id, but I would like for the SQL to actually be users.id. How can I write this?

Upvotes: 0

Views: 47

Answers (2)

Mohammad Shahadat Hossain
Mohammad Shahadat Hossain

Reputation: 1349

From your code what i understand your comment model would be.

class Comment < ActiveRecord::Base
  attr_accessible :id, :content, :user_id, :micropost_id

  belongs_to :user
  belongs_to :micropost
end

Then in your comments controller, which you access through the micropost_comments_path(@micropost) URL helper you can do the following to build the association in the create action:

def create
  @micropost = Micropost.find(params[:micropost_id])
  @comment = Comment.new(params[:comment])
  @comment.micropost = @micropost
  @comment.user = current_user

  if @comment.save
    ...
end

Upvotes: 0

trh
trh

Reputation: 7339

Remove the has_one declarations from your comment model. In this relationship, a comment will only ever have one user and one micropost, as denoted by belongs_to. Add has_one is confusing it.

Simplifying it should remove your error.

# app/models/comment.rb
class Comment < ActiveRecord::Base
  belongs_to :user
  belongs_to :micropost
end

Upvotes: 1

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