Re: [Rails] model association question

On 09/13/2011 03:34 PM, Jesse wrote:
> On 9/13/11 1:22 PM, Randy Regnier wrote:
>> I have a question about how best to model a pair of
>> properties/attributes in Rails3. The generic "models" are:
>>
>> class Foo < ActiveRecord::Base
>> end
>> class Bar < ActiveRecord::Base
>> end
>>
>> I want Foo to have two associations with Bar, along the lines of
>> 'has_one' for each association, where I can work with each, as in
>> bar1 and bar2. 'has_many' would work, but it would be extra work to
>> have to fish the correct one out of the array, and isn't as elegant a
>> way to model the relationships.
>>
>> Thanks
>>
>> Randy
>>
> I suppose that it could be done with a has_one relationship repeated
> as such
> class Foo < AR::B
> belongs_to :bar1, class_name => "Bar", :foreign_key => "bar1_id"
> belongs_to :bar2, class_name => "Bar", :foreign_key => "bar2_id"
> end
>
> Mind you this is not a very elegant way of doing it, but it is
> adhering to KiSS principles.
>
> On the Bar end of things, how should the relationship play out? Should
> it only be able to be associated to one Foo?
>
> Also are do bar 1 and bar 2 behave differently or have any
> characteristic that distinguish them. In other words, are all bar1's
> always going to be bar1's? if so you can do a normal has many
> relationship with a limit of 2 children and then scopes on the bar
> model to make up the difference.
>
> Jesse
>

Thanks.

On the Bar end, it would only be associated with the one Foo, yes.

bar1 and bar2 would have different values for their respective
properties, but that is about all. Well, I guess if a Foo got removed,
then so should both of its Bars, but I think I've seen how to do that part.

Randy

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