[Dbix-class] inheritance

[Hermida, Leandro]

Thank you for the reply,

Is there any way in the class definition to specify a default prefetch
attribute?  Otherwise in every place in the application where I do the
resultset search method on a concrete class I think I will have to put
the entire inheritance tree for that particular class, $attrs = {
prefetch => { 'parent_class' => { 'parent_of_parent_class' =>
'parent_of_parent_of_parent_class' } } }.

Leandro


Matt S Trout wrote:
> Create classes for them anyway, then have something like (in
TreatmentProtocol)
> 
> __PACKAGE__->might_have('_protocol', 'My::Schema::Protocol', undef, {
proxy => 
> [ qw/compound .../ ] });
> 
> then you can do $treatment_protocol->compound and it'll Just Work
(though 
> you'll need to specify the prefetch for _protocol to make it a single
query).
> 
> Hermida, Leandro wrote:
> > Hello,
> >  
> > I have a question about inheritance (or
generalization/specialization 
> > hierarchies?) when building your classes using DBIx::Class.  If I
have a 
> > data model with inheritance:
> >  
> > -- abstract class
> > create table parameterizable (
> >   id                INT NOT NULL
> >   ... some basic columns here...
> > );
> >  
> > -- abstract class
> > create table protocol (
> >   id                INT NOT NULL,
> >   name              VARCHAR(200)
> > );
> >  
> >  
> > create table growth_protocol (
> >   id                INT NOT NULL,
> >   medium            VARCHAR(200),
> >   temperature       VARCHAR(200)
> > );
> >  
> > create table treatment_protocol (
> >   id                INT NOT NULL,
> >   compound          VARCHAR(200),
> >   delivery_method   VARCHAR(200)        
> > );
> >  
> >  
> > alter table parameterizable
> >   ADD CONSTRAINT pk_id_01 PRIMARY KEY (id)
> > ;
> >  
> > alter table protocol
> >   ADD CONSTRAINT pk_id_02 PRIMARY KEY (id)
> >   ADD CONSTRAINT fk_id_02 FOREIGN KEY (id) REFERENCES
parameterizable (id)
> > ;
> >  
> > alter table growth_protocol
> >   ADD CONSTRAINT pk_id_03 PRIMARY KEY (id)
> >   ADD CONSTRAINT fk_id_03 FOREIGN KEY (id) REFERENCES protocol (id)
> > ;
> >  
> > alter table treatment_protocol
> >   ADD CONSTRAINT pk_id_04 PRIMARY KEY (id)
> >   ADD CONSTRAINT fk_id_04 FOREIGN KEY (id) REFERENCES protocol (id)
> > ;
> >  
> > How does one represent this using DBIx::Class?  Since abstract
classes 
> > like Parameterizable and Protocol should never get instantiated
directly 
> > then how do I create DBIx::Class packages for GrowthProtocol and 
> > TreatmentProtocol which will transparently join with the to the
abstract 
> > class tables and get the accessors when instantiating objects?