And placeholders. Definately placeholders. You won't have to worry about quoting then because it happens automatically (or even for some cases it saves a step or two internally)

my $sql = 'update upps_ret_q set state=?, message=? where seq_n=?';
my $sth = $dbh->prepare( $sql );
$sth->execute( $state, $msg, $key );
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__SIG__
use B;
printf "You are here %08x\n", unpack "L!", unpack "P4", pack
  "L!", B::svref_2object(sub{})->OUTSIDE;
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