From: Phrogz <phrogz@...>
Date: 2009-03-31T05:24:58+09:00
Subject: Re: activerecord query building question

On Mar 30, 12:30 pm, Aldric Giacomoni <"aldric[remove]"@trevoke.net>
wrote:
> I have this:
>
> require 'activerecord'
>
> class RefPhys < ActiveRecord::Base
>     set_table_name "tbRefPhys"
>     has_many :refphyslocations, :foreign_key => "refphysid"
> end
>
> class RefPhysLocation < ActiveRecord::Base
>     set_table_name "tbRefPhysLocations"
>     belongs_to :refphys, :foreign_key => "refphysid"
> end
>
> I want a list of the refphys names (in refphys) in a specific city (in
> refphyslocation).

For comparison with ActiveRecord (which I've all but forgotten now)
here's how you could do this in the Sequel[1] library:

  RefPhys.filter( :refphysid => refphyslocation.id )

The cool thing about Sequel is that until you ask it to go and fetch
the records, you have a Dataset object that you can keep filter. For
example:

  correct_location = RefPhys.filter( :refphysid =>
refphyslocation.id )

  # Further pare down the Dataset
  my_phys = correct_location.filter( :owner_id => me.id )

  # Filter to match multiple criteria, one of which is an array of
items
  my_open = my_phys.filter( :status => Status::OPEN_IDS, :hidden =>
false )

  my_open.each do |refphys|
    # Now you've run the single query and are running through the
results
  end

[1] http://sequel.rubyforge.org/