Something like (untested):
my ($curmag,$curiss,$curart)=();
my (%mag,%iss,%art);
while (my $d=fetchrow_hashref) {

  if (($curiss eq $$d{issue_number) &&
      ($curmag eq $$d{mag_name)) {
     push(@iss,{article_name=>$$d{article_name}});

  } else { # new issue and/or magazine
    $mag{issue_loop}=\@iss if (defined($curiss));
    @iss=[{article_name=>$$d{article_name}}]; # not sure if that assig
+ns a new ref. to array. Check FIRST!
    $curiss=$$d{issue_number}
  }
  if ($curmag ne $$d{mag_name}) {
     push(@data,\%mag) if defined($curmag);
     %mag={}; # see if that assigns new ref, as above
     $mag{mag_name}=$$d{mag_name};
     push(@data,\%mag) if defined($curmag);
     $curmag=$$d{mag_name};
  }
}

[download]
Issues that I'd have to do more testing with: You need to assign a NEW array, and a NEW hash in the code. Possibly I'd have to work with references from the start instead of having a @iss and %mag.

You'd want to do something so the last line closes up the whole thing (perhaps a "fake" row with "undef" elements).

Hope this helps...

In reply to Re: Idiomatic way of getting from database result set to HTML::Template data structure? by matija
in thread Idiomatic way of getting from database result set to HTML::Template data structure? by davehodg

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