所属协会-我怎么称呼它？

Question

Silly question, but I can't find an example . . .

My User model has_many Comments. My Comments model belongs_to User. The Comments table has a column user_id, which I've included in my db:seeds file. Every comment has a user_id.

So how do I refer to a comment's user? "Comment.user" seems like it should work, but I keep getting error messages saying user is nil, or an undefined method.

In particular, I want to refer to attributes of user through comment, such as comment.user.avatar.

Answer 1

Are you referring to the class Comment when you try and access the user, or the actual instance object? Doing something like the following should work:

@user = User.new(username: "Bob")
@comment = Comment.new(comment: "Hello World!", user: @user)
puts @comment.user.username

However, if you are doing Comment.user this will fail because you are not referencing a specific instance but rather the model itself. If so, that would explain what is causing your errors.

Answer 2

Stranger and stranger . . . today, I'm not getting the confusing error messages. So my code does work! Just in case people look up this question in the future, I'll do what I should've done in my question, and show more of my code. Again, Comments belongs_to User.

    - @comments.each do |com|
      = markdown com.body
      %small
        submitted
        = time_ago_in_words(com.created_at)
        ago by
        = image_tag(com.user.avatar.tiny.url) if com.user.avatar?
        = link_to((com.user.name || com.user.email), com.user)
        %br

Thanks for your input, @raznic!