Notification that can be updated

My website has a post feature where users can post messages. Additionally, users are able to edit the messages if there's a typo or if they want to add something.

Now, I want to set up a notification system that notifies other users of a post made by another user.

I can't store the Post record (with the message) in the notification, because it wouldn't reflect any edits made to the message, so I'm thinking that I store just the post_id in the notification and then retrieve the Posts using that.

How would I do this? How would I retrieve the Post record associated with the post_id in the notification?

via Chebli Mohamed