Post History

If I understand you correctly, you want to get the `last_edited_at` column for every child post, i.e. a list of last edit dates?

For this you should use

```ruby
post.children.map(&:last_edited_at)
```

which is a shorthand for

```ruby
post.children.map { |c| c.last_edited_at }
```

which iterates over the list of children and maps each to its `last_edited_at` timestamp.