SELECT 
 `pages`.`id` AS `pages_id`, 
 `pages`.`permalink` AS `pages_permalink`, 
 `pages`.`title` AS `pages_title`, 
 `pages`.`content` AS `pages_content`, 
 `pages`.`category_id` AS `pages_category_id`, 
 `pages`.`status` AS `pages_status`, 
 `categories`.`id` AS `categories_id`, 
 `categories`.`module` AS `categories_module`, 
 `categories`.`title` AS `categories_title`, 
 `categories`.`permalink` AS `categories_permalink`
FROM 
 `pages`
 LEFT JOIN categories ON `pages`.`category_id` = `categories`.`id`
WHERE (`categories`.`permalink` = "");