Rails Joins and include columns from joins table

Question

I don\'t understand how to get the columns I want from rails. I have two models - A User and a Profile. A User :has_many Profile (because users can revert back to an earlier

Answer 1

I have got round this problem by creating a VIEW in the database which is the join, and then referencing that as if it were a normal ActiveRecord table in the code. This is fine for getting data out of the database, but if you need to update it, then you'll need to go back to the base classes that represent the 'real' tables. I have found this method to be handy when doing reports that use biggish tables - you can get the data out all in one hit. I am surprised that this doesn't seem to be built into ActiveRecord, seems an obvious thing to me!

So for you:

IN SQL:

CREATE VIEW User_Profiles
AS
SELECT P.*, U.first_name
FROM Users U
inner join Profiles P on U.id=P.user_id

IN RUBY models file:

class UserProfile < ActiveRecord::Base
  self.primary_key = :id 
  #same dependencies as profiles
end

**HINT... I always forget to set the owner of the view (I use postgres), so it blows up straight away with much cursing and self-recrimination.