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-rails.html 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, > > > > > -- > > > You received this message because you are subscribed to the Google > Groups > > > "Ruby on Rails: Talk" group. > > > To post to this group, send email to [email protected] > . > > > To unsubscribe from this group, send email to > > > [email protected]<rubyonrails-talk%[email protected]> > <rubyonrails-talk%[email protected]<rubyonrails-talk%[email protected]> > > > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/rubyonrails-talk?hl=en. > > > > > > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Talk" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<rubyonrails-talk%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/rubyonrails-talk?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
