in reply to Class::DBI many to many delete

It should work. According to the docs, the default for cascading delete is to delete the child if the parent is deleted; but it's not working here. So, we have to work around it.

Class::DBI doesn't support Many to Many right now. The module's author does say that you can manually set up the relationships and get some measure of control by writing a Class::DBI::Cascade::Plugin::Nullify and inserting it into the relationship: 

WebR::M::CDBI::Datatype->has_many(children=>['WebR::M::CDBI::DatatypeR
+elationship'=>'child"], 'parent', {
   cascade => 'Class::DBI::Cascade::Plugin::Nullify'
});

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Try it and see if that works. I hope this helps.

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Re^2: Class::DBI many to many delete
by CassJ (Sexton) on Jul 18, 2006 at 00:12 UTC
    Odd. This works fine: 
        WebR::M::CDBI::DatafileRelationship->has_a(child=>'WebR::M::CDBI::
+Datafile');
    WebR::M::CDBI::DatafileRelationship->has_a(parent=>'WebR::M::CDBI:
+:Datafile');
    WebR::M::CDBI::Datafile->has_many(parents=>['WebR::M::CDBI::Datafi
+leRelationship' => 'parent'],'child', {
          cascade => 'Class::DBI::Cascade::Delete'});
    WebR::M::CDBI::Datafile->has_many(children=>['WebR::M::CDBI::Dataf
+ileRelationship' => 'child'],'parent', {
          cascade => 'Class::DBI::Cascade::Delete'} );

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    Ah - and if I do 
        WebR::M::CDBI::DatafileRelationship->has_a(child=>'WebR::M::CDBI::
+Datafile', {cascade=>'Class::DBI::Cascade::Delete'});

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    then the child datafiles get deleted too. Great! thanks! And, for the has_many relationships where I just want the FK to be nulled, rather than the record deleted: 
    package Class::DBI::Cascade::Nullify;

use base 'Class::DBI::Cascade::None';
use Data::Dumper;

sub cascade {
  my ($self, $obj) = @_;


  my $fk =$self->{_rel}->args->{foreign_key};
  foreach ($self->foreign_for($obj)){
    $_->$fk(undef); 
    $_->update;
  }
}

1;

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