Conditions on deep joins uses wrong table name

The example can be simplified to a single belongs_to, has_many relationship:

AnswerSet
  has_many :answers

Answer
  belongs_to :answer_set

Wrong query should look something like this: Answer.find(:all, :joins => { :answer_set => :answers }, :conditions => { :answer_set => { :answers => { :question_id => 1 } } })

Generates: SELECT "answers".* FROM "answers" INNER JOIN "answer_sets" ON "answer_sets".id = "answers".answer_set_id INNER JOIN "answers" answers_answer_sets ON answers_answer_sets.answer_set_id = answer_sets.id WHERE ("answers"."question_id" = 1)

Should generate: SELECT "answers".* FROM "answers" INNER JOIN "answer_sets" ON "answer_sets".id = "answers".answer_set_id INNER JOIN "answers" answers_answer_sets ON answers_answer_sets.answer_set_id = answer_sets.id WHERE ("answers_answer_sets"."question_id" = 1)

After thinking about this further, the root of the problem is how the conditions are built and doesn't have much to do with the joins.

The following should really error out with bad sql, but it doesn't:

Answer.find(:all, :conditions => { :answer_set => { :answers => { :question_id => 1 } } })

verified that patch applies and tests fail on 2-3-stable

-1 on fixing this issue. After looking closely at this I don't think a fix is worth the overhead. In order to reliably fix this the conditions would need to know about joins and how the joined tables are named. That is add_joins! would need to probably pass the JoinDependency back to add_conditions! in AR::Base (or else duplicate the naming scheme which seems to be asking for trouble). Such a change would be a major refactoring that I think needs to be considered more holistically, and not considered before Rails 3 in any case. In order to merit the additional complexity this would need to solve a whole class of problems, or else inspire a refactoring that made the :conditions/:joins code more expressive.

The workaround for this particular test case is simply to use:

:conditions => { :'posts_authors.title' => "Welcome to the weblog" }

instead of:

:conditions => { :author => { :posts => { :title => "Welcome to the weblog" } } }

verified

-1 I agree with Gabe on this one, the re-factoring it would take for this could cause more issues then it solves.

At the point the developer is adding :join and :conditions they are already making an informed choice based off of their knowledge of the database schema, i do not feel manually specifying table names is that much added work
(ideally these types of things should be pulled into the model anyway where it's more proper for it to 'know' about its relationships / naming conventions)