Ruby on Rails - 子弹宝石。 添加到您的查询中： .includes([:author])

Question

I have an N+1 Query issue, but I dont understand how to fix the issue.

I have a User model, Post model and Comment Model.

User has many posts 
User has many comments 

Post belongs to User
Post has many Comments 

Comments belong to user 
Comment belongs to post

In my post controller, I have

def index
    @posts = Post.includes(:author).where(author_id: params[:user_id])
end


def show
    @post = Post.includes(:author).find(params[:id])
end

When I load the Posts show view below...

I get these two warnings from Bullet Gem

user: espada
GET /users/2/posts/6
USE eager loading detected
  Comment => [:author]
  Add to your query: .includes([:author])
Call stack

user: espada
GET /users/2/posts/6
USE eager loading detected
  Comment => [:post]
  Add to your query: .includes([:post])
Call stack

I have tried to add the two .includes in various actions, tried many things for the past 5 hours...nothing works. At this point, I want to understand where do I add those two includes?

And how does one interpret that message?

Answer 1

Its showing an error on the comments model

Try This

def index
    @posts = Post.includes(:author, comments: %i[author post]).where(author_id: params[:user_id])
end


def show
    @post = Post.includes(:author, comments: %i[author post]).find_by_id(params[:id])
end

Answer 2

You're probably looking for a dependency on comments, not on posts. So you have to include it like this.

Post.includes(:author, comments: [:author, :post]).find(params[:id])

Answer 3

Thanks to Larkin who mentioned that the problem could be in the view, I went and looked at my Post index and Post show view.

In my post show and index views, I was rendering a partial for the comments with

<%= render partial: "shared/post/comment_card", locals: { post: @post, comments: @post.comments} %>

In my comment card I had a delete button

<%= button_to "Delete Comment", user_post_comment_path(comment.author, comment.post, comment), 
      method: :delete, data: { confirm: "Are you sure?" } %>

That is where the warning was coming from when I get the post for each comment. I realized that since I had passed in the post via locals I could write my delete button as

<%= button_to "Delete Comment", user_post_comment_path(comment.author, post, comment), 
          method: :delete, data: { confirm: "Are you sure?" } %>

That fixed that error.

However, I also had to change my show action because trying to get a post without comments was raising a warning, so I wrote it as

  def show
    @post = Post.includes(:author).find(params[:id])
    @post = Post.includes(:author, comments: [:author]).find(params[:id]) if @post.comments.any?
  end