FindIds
=======

Sometimes, I find myself writing code as follows,

User.find_all_by(...).map(&:id)

I finally decided to write an extension to ActiveRecord finders which select only the primary key of the model while respecting all the finder options. This extention adds :all_ids, :first_id, :last_id options to the ActiveRecord finders.

I'm using Rails 2.3.x currently ... so I don't know at the moment if it works with anything else.

What's a good way to test this?

Example
=======

All the normal cases,

>> User.find(:all_ids, :condition => [ "first = ?", "Paul" ])
=> [1, 2]

>> User.find(:all_ids, :condition => [ "first = ?", "Paul" ], :order => "id desc")
=> [2, 1]

>> User.find(:first_id, :condition => [ "first = ?", "Paul" ])
=> 1

>> User.find(:first_id, :condition => [ "first = ?", "Paul", :order => "id desc"])
=> 2

>> User.find(:last_id, :condition => [ "first = ?", "Paul" ])
=> 2

>> User.find(:last_id, :condition => [ "first = ?", "Paul", :order => "id desc"])
=> 1

and of course all the dynamic finders as well,

>> User.find_all_ids_by_first("Paul")
=> [1, 2]

>> User.find_id_by_first("Paul")
=> 1


Copyright (c) 2009 Paul Kmiec, released under the MIT license