postgresql 7.1 select 1 where exists (select 1 from ec_categories) select p.product_id, p.product_name, p.one_line_description, o.offer_code from ec_products_searchable p left outer join ec_user_session_offer_codes o on (p.product_id = o.product_id and user_session_id = :user_session_id) where not exists (select 1 from ec_category_product_map m where p.product_id = m.product_id) order by p.product_name