Thanks for your replies Yong Gu. I believe the article was exactly the
information I was seeking.

Cheers,
brianp

On Mar 30, 12:39 am, Yong Gu <[email protected]> wrote:
> I am sorry that i do not have too much ideas about whether STI(Single Table
> Inheritance) are good or not, it depends.
>
> here is article(not mine) you could refer:
>
> http://code.alexreisner.com/articles/single-table-inheritance-in-rail...
>
> I hope that could help you
>
> On Tue, Mar 30, 2010 at 3:30 PM, brianp <[email protected]> wrote:
> > Hmmm.... This could lead to 60+ blank fields a record (for that
> > table). Is that bad design, is there a better method I should explore?
> > Or is this just normal and I should go with it?
>
> > On Mar 30, 12:23 am, Yong Gu <[email protected]> wrote:
> > > yes, the Animal contains all the field and if you create a Feline
> > instance
> > > as feline, seeing_eye_dog will be left empty.
>
> > > On Tue, Mar 30, 2010 at 3:19 PM, brianp <[email protected]>
> > wrote:
> > > > I've done some reading on Single Table Inheritance.
>
> > > > I think I need something a little more though.
>
> > > > Classic example.
>
> > > > class Animal < ActiveRecord::Base
> > > >    // db fields:
> > > >                name: string
> > > >                age: int
> > > >                type: string
> > > >                breed: string
> > > > end
>
> > > > class Feline < Animal
> > > >    // db fields:
> > > >                whisker_count: int
> > > > end
>
> > > > class Canine < Animal
> > > >   // db fields:
> > > >                seeing_eye_dog: boolean
> > > > end
>
> > > > So how do Canine and Feline inherit the fields from Animal although
> > > > they don't require each others fields. Does the Animals table just
> > > > contain all the fields but value can be null and only returns the
> > > > available fields for that Model?
>
> > > > Cheers,
>
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