[Dbix-class] Error with +columns

[Peter Rabbitson]

On Fri, Dec 14, 2012 at 12:48:22PM -0800, mpm wrote:
> I am getting an error, that was not happening before:
> 
> my $where_o={};
>                 my $attr_o={};
>                 my @og;
>                 $where_o->{'me.m_id'}= $m_id;
>                 $where_o->{'sp.is'}='y';
>                 push @{ $attr_o->{join} }, {'tD' => {'g' => 'sp'}};
>                 $attr_o->{group_by}='me.t_id';
>                 $attr_o->{'+columns'}= [ qw/tD.o_id/];
>                 my
> $ogs=$c->model('weight::T2m_id')->search($where_o,$attr_o);
>                 while (my $rs_ogs = $ogs->next()) {
>                         my $o_group=$rs_ogs->get_column('tD.o_id');
>                         push @o_groups,$o_group;
>                 }
>                 $c->stash->{o_groups}=\@o_groups;

This code is extremely weird, and I am not sure how old of a DBIC you 
had *before* upgrading that would allow it to work. In fact I honestly 
have no idea how did get_column('foo.bar') ever work for you - is there 
perhaps more code that you are not showing us? On any DBIC version in 
*at least* the past 4-5 years this would throw with "no such column 
tD.o_id"

In any case, the above is better/clearer written as:

$c->stash->{o_groups} = [
  $c->model('weight::T2m_id')->search(
    {
      'me.m_id' => $m_id,
      'sp.is' => 'y',
    },
    {
      join => {'tD' => {'g' => 'sp'}},
      distinct => 1,
    }
  )->get_column('tD.o_id')->all
];

Note - the get_column I used[1] is *different* than the get_column you
used[2].

Let us know if you have further questions.

Cheers

[1] https://metacpan.org/module/DBIx::Class::ResultSet#get_column
[2] https://metacpan.org/module/DBIx::Class::Row#get_column