Change resource param in Phoenix routes

Phoenix, like Rails, gives you the option to specify a resource in your routes in order to generate the typical CRUD actions we deal with in a controller. The dynamic segment which identifies the resource is :id by default.

resources "orders", OrderController

The update route would look like this if we run mix phoenix.routes.

order_path  PATCH  /orders/:id    MyApp.OrderController :update

If our table doesn't use "id" as a primary key, or we want to change the field we use to find our resource, we can specify it as an option in our route:

resources "orders", OrderController, param: "some_field"

Now our route is updated:

order_path  PATCH  /orders/:some_field    MyApp.OrderController :update

https://github.com/phoenixframework/phoenix/blob/master/lib/phoenix/router.ex#L482