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foreach (@fields) {
   
...
  
  $sth->execute(values %$_);
}

# list your headers
my @heading = qw[description billing_code user_id 
...
foreach my $row (@fields) {
   $sth->execute( map { $row{$_} } @heading );
}

my @heading;
{
...
   $sth->execute;
   @heading = @{ $sth->{NAME_lc} };
}