Rails - Feb 2008 - Find all models that do not have any associated models

Recipes has many flavors
Flavor belongs_to Recipe

How would I find and list all recipes that do not have any associated
flavors?

I am running a nightly report that is looking for all recipes which are
missing flavors to let the user know that they neeed to create some
flavors for those recipes.

Thanks!
-- 
Posted via http://www.ruby-forum.com/.

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I don''t have a direct answer, but a general solution to that problem
would be with validations in the model.


-Thufir
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On 12 Feb 2008, at 23:31, Jason Matthew wrote:
>
> Recipes has many flavors
> Flavor belongs_to Recipe
>
> How would I find and list all recipes that do not have any associated
> flavors?
>
> I am running a nightly report that is looking for all recipes which  
> are
> missing flavors to let the user know that they neeed to create some
> flavors for those recipes.
The sql you need is left outer join, ie something like

Recipe.find :all, :joins => ''left outer join flavours on recipe_id =
recipes.id'',
                   :conditions => ''flavours.id is null'',
                   :select => ''recipes.*''

(the :select clause is unneeded on rails 2.0 - rails adds it for you)

Fred
>
>
> Thanks!
> -- 
> Posted via http://www.ruby-forum.com/.
>
> >

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