[Dbix-class] Updating many-to-many relationships

[Alexander Hartmaier]

You can find an example in the many_to_many relationship bridge docs:
https://metacpan.org/module/DBIx::Class::Relationship#many_to_many

Am 2012-02-21 17:11, schrieb David Cantrell:
> I have a bunch of classes set up as part of the ACL system for this 'ere
> application what I'm writing.  There is a 'user' table, a 'role' table,
> and sitting in between them a 'user_role' table.  Users can have any
> arbitrary combination of roles, so this is yer classic many-to-many
> situation. Pared down to the minimum, the classes are:
>
>   package Database::Result::User;
>   use base 'DBIx::Class::Core';
>   __PACKAGE__->table('user');
>   __PACKAGE__->add_columns(
>     id       => { data_type => 'INT',  is_nullable => 0 }, # autoinc
>     status   => { data_type => 'CHAR', is_nullable => 0 },
>     username => { data_type => 'CHAR', is_nullable => 0 }
>   );
>   __PACKAGE__->set_primary_key( "id" );
>   __PACKAGE__->has_many( "user_roles", "Database::Result::UserRole", { 'foreign.user_id' => "self.id" } );
>   1;
>
>   package Database::Result::UserRole;
>   use base 'DBIx::Class::Core';
>   __PACKAGE__->table('user_role');
>   __PACKAGE__->add_columns(
>     user_id => { data_type => 'INT', is_nullable => 0 },
>     role_id => { data_type => 'INT', is_nullable => 0 },
>   );
>   __PACKAGE__->set_primary_key( qw(user_id role_id) );
>   __PACKAGE__->belongs_to("user", "Database::Result::User", { 'foreign.id' => 'self.user_id' });
>   __PACKAGE__->belongs_to("role", "Database::Result::Role", { 'foreign.id' => 'self.role_id' });
>   1;
>
>   package Database::Result::Role;
>   use base 'DBIx::Class::Core';
>   __PACKAGE__->table('role');
>   __PACKAGE__->add_columns(
>     id   => { data_type => 'INT',  is_nullable => 0 }, # autoinc
>     name => { data_type => 'CHAR', is_nullable => 0 },
>   );
>   __PACKAGE__->set_primary_key( "id" );
>   __PACKAGE__->has_many( "user_roles", "Database::Result::UserRole", { 'foreign.role_id' => "self.id" } );
>   1;
>
> I can create users with roles easily, creating roles on the fly if
> necessary:
>
>   my $person = ...->create({
>     username   => 'anselm',
>     status     => 'alive',
>     user_roles => [
>       { role => { name => 'Monk' } },
>       { role => { name => 'Archbishop' } },
>     ]
>   });
>
> I couldn't see this documented anywhere, but found it in the mailing
> list archives.  It creates any necessary entries in the 'role' table,
> and in the 'user_role' table.
>
> However, I can't find any nice way of updating a user's
> roles, something like this (which I tried, but it doesn't work) ...
>
>   $person->status('dead');
>   $person->user_roles([
>     { role => { name => 'Saint' } }
>   ]);
>   $person->update();
>
> Am I missing something?  It would make my life ever so pleasant if there
> were a nice easy way of doing this.  As it is, however, the call to the
> user_roles() method is not having any effect at all - there's no queries
> generated whatsoever for it, just the UPDATE to change the status from
> alive to dead.
>


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