postgresql7.1
select attr_id
from (select attr_id, sort_key
from ab_contact_attrs
where sort_key $operator (select sort_key
from ab_contact_attrs
where attr_id = :attr_id) and
contact_id = :contact_id)
order by sort_key $direction
limit 1
select ab_contact_attr__swap_sort(:attr_id, :other_attr_id);