my($id, $name, $phone);
$sth->bind_columns(undef, \$id, \$name, \$phone);

##</code><code>##

$sth->bind_columns(\my ($id, $name, $phone));

##</code><code>##

select stuff
from table
where field1 in (?,?,?,?)
and   field2 in (?,?,?,?,?)