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Finder methods ignore :include in has_many :through

#1845

If an has_many :through association has an :include and :conditions in it, calling a finder method on it will fail if the conditions refer to the included table, because the :include is ignored.

With this simple class definitions:


class Author < ActiveRecord::Base
has_many :authorships
has_many :books_with_preview, :source => :book,
         :through => :authorships, :include => :chapters,
         :conditions => ['chapters.preview = 1']
end

class Authorship < ActiveRecord::Base
belongs_to :author
belongs_to :book
end

class Book < ActiveRecord::Base
has_many :authorship
has_many :chapters
end

class Chapter < ActiveRecord::Base
belongs_to :book
end

you can call


author.books_with_preview

but the following call will fail:


author.books_with_preview.find(:all)

I'm using rails 2.1.0 but I've been told that it's the same in rails 2.2.2. I tested mysql and sqlite, and I get the same error:

ActiveRecord::StatementInvalid: Mysql::Error: Unknown column 'chapters.preview' in 'where clause': SELECT books.* FROM books INNER JOIN authorships ON books.id = authorships.book_id WHERE ((authorships.author_id = 1) AND ((chapters.preview = 1)))

Reported by Eduardo · February 2nd, 2009 @ 04:07 PM

Activity

JackC
- Tag changed from :include, :through, finder to :include, :through, eagerloading, eager_loading, find, finder
This is also an issue in 2.3 RC1.

I've also found that all works even the find(:all) doesn't.

It seems to be fixable by inserting the following line at line 52.
```
options[:include] = @reflection.options[:include]
```
But I don't know enough about the ActiveRecord internals to know if this will break something.
February 18th, 2009 @ 05:27 PM
JackC
Line 52 of active_record/associations/association_collection.rb that is.

February 18th, 2009 @ 05:28 PM
CancelProfileIsBroken
- Tag changed from :include, :through, eagerloading, eager_loading, find, finder to :include, :through, bugmash, eagerloading, eager_loading, find, finder
August 5th, 2009 @ 01:47 PM
railsbob
verified

This error is reproducible. The error is caused because options[:include] was assigned nil in has_many_through_association.rb.
```
def construct_find_options!(options)
  options[:select]  = construct_select(options[:select])
  options[:from]  ||= construct_from
  options[:joins]   = construct_joins(options[:joins])
  options[:include] = @reflection.source_reflection.options[:include] if options[:include].nil? 
end
```
options[:include] should not be nil, because the reverse_merge! prohibits assignment from @reflection.options[:include] in merge_options_from_reflection!(options) method (association_proxy.rb), even if the value is nil.
The solution is not to have options[:include] if the value is nil and appropriate :include options are picked from reflection.

I have attached a patch with corresponding test, which fixed the issue.
- 1845_fixed_has_many_through_find.diff 2.18 KB
August 9th, 2009 @ 01:08 PM
Hugo Peixoto
+1 railsbob's patch works fine in both 2-3-stable and master, and without the fix the test fails.

August 9th, 2009 @ 01:29 PM
Rizwan Reza
verified

+1 The patch works perfectly under master and 2-3-stable. All tests pass.

August 9th, 2009 @ 03:06 PM
David Trasbo
+1

Bug verified to be reproducible. Patch applies cleanly to edge Rails and all tests are passing.

August 9th, 2009 @ 04:00 PM
Repository
- State changed from new to resolved
(from [076ca48bd649ddea4dd1a320879c03a9fe7a0a6d]) Ensure hm:t#find does not assign nil to :include [#1845 state:resolved]

Signed-off-by: Pratik Naik pratiknaik@gmail.com
http://github.com/rails/rails/commit/076ca48bd649ddea4dd1a320879c03...

August 9th, 2009 @ 05:06 PM
Repository
(from [80d8608102cce64805e7573f6b97d8561f7f11ea]) Ensure hm:t#find does not assign nil to :include [#1845 state:resolved]

Signed-off-by: Pratik Naik pratiknaik@gmail.com
http://github.com/rails/rails/commit/80d8608102cce64805e7573f6b97d8...

August 9th, 2009 @ 05:06 PM
CancelProfileIsBroken
- Tag changed from :include, :through, bugmash, eagerloading, eager_loading, find, finder to :include, :through, eagerloading, eager_loading, find, finder
- Milestone cleared.
August 9th, 2009 @ 05:13 PM
Josh N. Abbott
Has this issue really been resolved? I'm running Rails 2.3.4 and when I try to load a has_many :through association, the construct_find_options! method doesn't get called. The find_target method is what gets called and in spite of the fact that it appears that the :include option is getting passed to the subsequently called 'find' method, the associations are being ignored.

Another odd thing is that when I call #count on the association everything loads fine.

So the question is, did this patch actually solve the original problem the ticket was opened for? It seems to me that it didn't.

November 17th, 2009 @ 07:50 PM