class AddDeletedAtToPosts < ActiveRecord::Migration[6.1]
def change
add_column :posts, :deleted_at, :datetime
add_index :posts, :deleted_at
end
end
class Post < ApplicationRecord
acts_as_paranoid
belongs_to :author, class_name: 'User'
has_many :comments, dependent: :destroy
validates :title, presence: true
# Custom scope to find recently deleted posts
scope :recently_deleted, -> { only_deleted.where('deleted_at > ?', 7.days.ago) }
end
module Api
module V1
class PostsController < BaseController
def destroy
post = current_user.posts.find(params[:id])
post.destroy
render json: { message: 'Post deleted successfully' }, status: :ok
end
def restore
post = current_user.posts.with_deleted.find(params[:id])
post.restore
render json: post, status: :ok
end
end
end
end
Hard deletes make data recovery impossible and complicate audit trails. Soft deletes mark records as deleted without removing them from the database, preserving history and enabling undo functionality. The paranoia gem adds a deleted_at timestamp column and overrides ActiveRecord's destroy method to set the timestamp instead of running DELETE. Queries automatically exclude soft-deleted records unless you use with_deleted or only_deleted scopes. This is valuable for user accounts, content moderation, and any domain where accidental deletion is costly. The downside is that unique indexes need to account for deleted records, and table sizes grow over time. I periodically archive truly old deleted records to separate tables.