Exercise: Customize Your Repo Module

Problem statement

We’d like to have an easy way to get the newest record in each of our database tables. The tables in our sample database all have an inserted_at column that contains a timestamp of when the records are inserted. We’d like to make it easy to get the newest timestamp of any given table.

Coding challenge

Write a function called newest for the Repo module that takes a table name as an argument and returns the :inserted_at value for the most recently-added record of the table.