Beefy Boxes and Bandwidth Generously Provided by pair Networks
P is for Practical
 
PerlMonks  

Re: Class::DBI and DB design

by tunaboy (Curate)
on Jun 06, 2003 at 22:15 UTC ( #263874=note: print w/ replies, xml ) Need Help??


in reply to Class::DBI and DB design

I have a little more time now so I figured I might as well show how I would alter your schema to work with Class::DBI (I am not claiming this is the way you should do it, merely how I would):

package My::User; use base 'My::ClassDBI'; __PACKAGE__->table ('user'); __PACKAGE__->columns ( All => qw( uid name login ) ); __PACKAGE__->has_many( 'capabilities', 'My::UserCapability' => 'user' +); ### package My::Capability; use base 'My::ClassDBI'; __PACKAGE__->table ('capability'); __PACKAGE__->columns ( All => qw( capid name default ) ); __PACKAGE__->has_many( 'users', 'My::UserCapability' => 'capability' ) +; ### package My::UserCapability; use base 'My::ClassDBI'; __PACKAGE__->table ('user_capability'); # note the added primary key idx __PACKAGE__->columns ( All => qw( idx user capability ) ); __PACKAGE__->has_a( 'user' => 'My::User' ); __PACKAGE__->has_a( 'capability' => 'My::Capability' );

You could now print out all the capabilities for a user with:

foreach ( $user->capabilities() ) { print $_->capability->name(), "\n"; }
or all the users with a certain capability:
foreach ( $capability->users() ) { print $_->user->name(), "\n"; }
The users and capabilities methods might be better named as they don't really return a list of users or capabilites but rather return a list of My::UserCapability objects. But you could write a custom get_capabilities method such as:
sub get_capabilities { my ( $self ) = @_; my @capabilities = $self->capabilities(); return map { $_->capability->name() } @capabilities; }

It is a bit of work getting around the single primary key limitation of Class::DBI but IMHO well worth it.

NOTE: I think all the code is correct as given but I could be drastically wrong as it is late on a Friday afternoon.


Comment on Re: Class::DBI and DB design
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://263874]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chanting in the Monastery: (8)
As of 2015-07-07 06:06 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (87 votes), past polls