Rails - Aug 2006 - Eager loading wierdness

Consider this problem.

I have an Item that has_many Features

I want to find all Items with a Feature name of ''foo''.

Normally you would do this..

@items = Item.find(:all, :conditions=>["features.name = ?",
''foo''],
:include=>:features)

This all works fine and dandy except for this problem.

If you do this...

<% for item in @items %>
<%= item.features.map {|x| x.name}.to_sentence %>
<% end %>

you only get the features listed that match the search criteria.  If the  
item object has 10 different features associated and you search for one,  
the .features association only returns the one you searched on instead  
of the entire list of associated objects.

Anyone know of a way to structure the search to return them all short of  
reloading each object?

BTW: Rails 1.1.4

_Kevin
www.sciwerks.com
-- 
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On 7-Aug-06, at 7:33 AM, Kevin Olbrich wrote:
> Consider this problem.
>
> I have an Item that has_many Features
>
> I want to find all Items with a Feature name of ''foo''.
>
> Normally you would do this..
>
> @items = Item.find(:all, :conditions=>["features.name = ?",
''foo''],
> :include=>:features)
>
> This all works fine and dandy except for this problem.
>
> If you do this...
>
> <% for item in @items %>
> <%= item.features.map {|x| x.name}.to_sentence %>
> <% end %>
>
> you only get the features listed that match the search criteria.   
> If the
> item object has 10 different features associated and you search for  
> one,
> the .features association only returns the one you searched on instead
> of the entire list of associated objects.
>
> Anyone know of a way to structure the search to return them all  
> short of
> reloading each object?
>
Hey Kevin,

you could reduce db hits like this (off the top of my head, not tested):

item_ids = Item.find(:all, :select => ''distinct items.id'',
   :joins => ''inner join features on features.item_id =
items.id'',
   :conditions => [''features.name = ?'',
''foo'']
)

@items = Item.find(:all,
   :conditions => [''items.id in (?), item_ids.collect(&:id)],
   :include => :features
)

HTH,
Trevor
> BTW: Rails 1.1.4
>
> _Kevin
> www.sciwerks.com
> -- 
> Posted with http://DevLists.com.  Sign up and save your mailbox.
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