How to order associated columns case insensitive

Question

I'm trying to order all my projects by their customer company names, but I get this error: PG::UndefinedTable: ERROR: missing FROM-clause entry for table "customers" LINE 1: ... WHERE "projects"."archived" = $1 ORDER BY LOWER(customers.... ^ : SELECT "projects".* FROM "projects" WHERE "projects"."archived" = $1 ORDER BY LOWER(customers.company) ASC.

This is how I tried it so far:

projects = Project.includes(:customer).order("LOWER(customers.company) ASC")

If I leave out LOWER(…) everything works fine.

Answer 1

You need to write it using references.

Project.includes(:customer)
       .order("LOWER(customers.company) ASC")
       .references(:customers)