Querying has_many Associations

Upcase
1
This is a companion discussion topic for the original entry at https://thoughtbot.com/upcase/videos/advanced-querying-has-many.
5

This is great stuff! So, you mean to tell me ActiveRecord will only make 1 query for all this?!

I’ve literally implemented very similar queries using Enumerable… This is a total game changer!

6

Hi, thanks for this tutorial!

Just to let you know that the tables names in the examples under the ‘Gluing tables together with the joins method’ section are mismatched; for instance the locations table is labelled ‘people’

Thanks

Andrea

7

Is there any way of merging more than one queries without being longwinded?

People.joins(location: :region).merge(Region.order(:name)).merge(Location.order(:name)).order(:name)

Does this work?

People.joins(location: :region).merge(Region.order(:name), Location.order(:name)).order(:name)

8

@JalenOng

it’s possible to rewrite the query using this format, it’s based on @christoomey solution https://exercises.upcase.com/exercises/advanced-activerecord-querying-belongs_to-associations/solutions/christoomey :
People.joins(location: :region).order("regions.name, locations.name, name")