Facebook-Clone/db/migrate/20180613072627_create_comments.rb

class CreateComments < ActiveRecord::Migration[5.2]
  def change
    create_table :comments do |t|
      t.integer :author_id,null:false
      t.text :body,null:false
      t.integer :post_id,null:false
    end
    add_index :comments,:author_id
    add_index :comments,:post_id
  end
end