This view shows a list of authors along with the title of their newest post and the date that it was published. It implements a Greatest Per Group query – thus, avoiding the N+1 query problem – using a scoped has_one assocation.

View the source code:

Read the blog post explaining this approach.

Author Newest Post Published
J.D. Salinger Franny and Zooey 1961-01-01
Jane Austen Persuasion 1817-01-01
Charles Dickens Barnaby Rudge 1841-01-01

About this App

This Ruby on Rails app demonstrates the concepts encompassed in a series of blog posts about Greatest Per Group queries in Rails. You can view the source code on Github.