The Code

  my $q = $d->query( 'find_author', {
              author => \$author,
          });

  $q->prepare();
  $q->execute(author => 'Larry Wall');
  while ( my $row = $q->fetchrow_hashref ) {
      last if $row->{title} eq 'Programming perl'; # 1st 'pink' edition ;)
  }
  $q->finish();

• substitution variables are used as placeholders
• substitution values are passed as arguments
• change value without a need for a prepare
• fetch* family can perform automatic execute