virtualmind-ror-a.rb

# app/models/topic.rb
class Topic < ApplicationRecord
  self.table_name = 'topic'
  
  ## Associations
  has_many :posts
  
  ## Validations
  validates :name, presence: true
end

# app/models/post.rb
class Post < ApplicationRecord
  self.table_name = 'post'
  
  ## Associations
  belongs_to :topic
  
  ## Validations
  validates :title, presence: true
  validates :text, presence: true
end

# db/schema.rb
ActiveRecord::Schema.define(version: 1) do
  create_table "topic", force: :cascade do |t|
    t.string "name", limit: 255, null: false
  end
  
  create_table "post", force: :cascade do |t|
    t.bigint "topic_id", null: false
    t.text "title", null: false
    t.text "text", null: false
    t.index ["topic_id"], name: "index_post_on_topic_id"
  end
  
  add_foreign_key "post", "topic"
end