Refactoring Ruby Iteration Patterns to the Database
Apr 16, 2014 · 1 minute readCheck out my recent article on thoughtbot’s blog.
Frequently on projects we need to run a calculation through an ActiveRecord association. For example, we might want to get a user’s all time purchases, a company’s total amount of products sold, or in our case, the total amount of loans made to a campaign. This sort of calculation is ripe for using a map and an inject but frequently the solution is more elegant and faster if we can have SQL do the work instead.