OK I know this code is hideous, believe me. That's why I'm seeking the wisdom! It's more of a logic problem than simply a Perl problem, but...

I'm getting some data out of SQL (fetchrow_hashref) in the form: 

{season => 1, ep => 1, title => 'Hellmouth' },
{season => 1, ep => 2, title => 'Harvest'   },
{season => 1, ep => 3, title => 'Witch'     },
{season => 1, ep => 4, title => 'Teacher'   },
{season => 1, ep => 5, title => 'First Date'},
  # [etc]
{season => 2, ep => 13, title => 'Bad'      },
{season => 2, ep => 14, title => 'Assembly' },
{season => 2, ep => 15, title => 'School'   }

[download]

That is, it's a long list of episodes, some in season n, some in season n+1 and so on. I need to put it into a structure like this: 

$appearances = 
[
    {season => 1, eps => 
      [ 
        {title => 'Hellmouth' },
        {title => 'Harvest'   },  
        {title => 'Witch'     },    
        {title => 'Teacher'   },  
        {title => 'First Date'}
      ]
    },
    
    {season => 2, eps => 
      [ 
        {title => 'Bad'       },
        {title => 'Assembly'  },
        {title => 'School'    },
      ]
    }
]

[download]

An array of hashes for each season, and each episode an entry in an array within that hash.

Here's how I did it late last night, and it works, but there must be a better way than this: 

my $temp_hash   = {};
my $last_season = 0; 
my $appearances = [];
while ( my $ref = $sth->fetchrow_hashref() ) {
    if ( $ref->{season} != $last_season ) {
        # if the season has changed, unless
        unless ( $last_season == 0 ) {
            # unless it's the first season we encounter
            push( @{$appearances}, $temp_hash );
                # put the data for that season into 
                # the data structure
            $temp_hash = {};
               # make the hash empty again
        }
    }
    $temp_hash->{'season'} = $ref->{'season'};
     push( @{ $temp_hash->{'eps'} }, { title => $ref->{'title'} } );
    $last_season = $ref->{season};
    # put the season into the marker variable
}
push( @{$appearances}, $temp_hash );
    # need to put what's left over into the data 
    # structure after the while() finishes.

[download]

Where I build little structures and append them onto the big structure by watching for a change of season, with extra clauses for the first time around and so on.

I await your advice. Please be kind.

Update: Forgot to say, yes the data comes out in the right order, that's not part of the problem, and no, it's not an HoAoH, is it? It's an AoHoWhatever.


($_='kkvvttuubbooppuuiiffssqqffssmmiibbddllffss')
=~y~b-v~a-z~s; print

In reply to building an HoAoH ... very badly by Cody Pendant

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