has_many_through_associations bug when set_primary_key used

I have three classes defined like this:

class Campaign < ActiveRecord::Base

  has_many :urls, :foreign_key => 'campaignid'   has_many :stats, :through => :urls

  set_table_name 'campaign'   set_primary_key 'campaignid' end

class Url < ActiveRecord::Base   belongs_to :campaign, :foreign_key => 'campaignid'   has_many :stats, :foreign_key => 'urlid'

  set_table_name 'url'   set_primary_key 'urlid' end

class Stat < ActiveRecord::Base   belongs_to :url, :foreign_key => 'urlid'

  set_primary_key 'statsid' end

When I drop into the console and try this:

c = Campaign.find(:first) c.stats

I get this:

ActiveRecord::StatementInvalid: Mysql::Error: #42S22Unknown column 'url.statsid' in 'on clause': SELECT `stats`.* FROM `stats` INNER JOIN url ON stats.urlid = url.statsid WHERE ((`url`.campaignid = 1))         from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:147:in `log'

It looks like the inner join is being improperly constructed. It should say

INNER JOIN ON stats.urlid = url.urlid

Or, to put it more generically:

INNER JOING ON <association_table>.<intermediate_table_fk> = <intermediate_table>.<intermediate_table_pk>

But it is currently doing:

INNER JOING ON <association_table>.<intermediate_table_fk> = <intermediate_table>.<associate_table_pk>

I think this boils down to activerecord-2.1.0/lib/active_record/associations/has_many_through_association.rb:150-155

I think this would be easy to miss since :through associations aren't entirely common and renaming your primary key is also not common so any table's primary key is getting used. I'm going to do a workaround that doesn't use the :through association for now.

I think this would be easy to miss since :through associations aren't entirely common and renaming your primary key is also not common so any table's primary key is getting used. I'm going to do a workaround that doesn't use the :through association for now.

Hi there,

this definitely sounds like you've found a bug. The best bet would be to jump into the #rails-contrib irc channel on freenode, and ask for some help coming up with a patch to fix this, and include tests.

The mechanics of contributing a git patch are covered in:

http://rails.lighthouseapp.com/projects/8994/sending-patches