btrc-hub/backend/app/models/post.rb

class Post < ApplicationRecord
  belongs_to :parent, class_name: 'Post', optional: true, foreign_key: 'parent_id'
  belongs_to :user, foreign_key: ''
  has_many :post_tags, dependent: :destroy
  has_many :tags, through: :post_tags
  has_many :user_post_views, dependent: :destroy
end