Выбрать все записи с таблицы ah_gallery но не более чем 10 с каждой категории

set @n=1, @i=0, @p=0;

select `ah_categories`.`id`, `ah_categories`.`title` from `ah_gallery` LEFT JOIN `gallery_category` ON `ah_gallery`.`id` = `gallery_category`.`gallery_id` LEFT JOIN `ah_categories` ON `gallery_category`.`category_id` = `ah_categories`.`id` where if(@p=`ah_categories`.`id`, @i:=@i+1,(@i:=0) or (@p:=`ah_categories`.`id`)) and @i<@n ORDER BY `ah_gallery`.`id` DESC;

CREATE TABLE IF NOT EXISTS `ah_gallery` (
  `id` mediumint(9) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL,
  `bullet` text NOT NULL,
  `description` text NOT NULL,
  `price` float NOT NULL DEFAULT '0',
  `price_muted` float DEFAULT NULL,
  `created` int(11) NOT NULL,
  `updated` int(11) NOT NULL,
  `status` tinyint(4) NOT NULL DEFAULT '1',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

CREATE TABLE IF NOT EXISTS `ah_categories` (
  `id` smallint(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `pseudo` varchar(50) NOT NULL,
  `status` tinyint(4) NOT NULL DEFAULT '1',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

CREATE TABLE IF NOT EXISTS `gallery_category` (
  `gallery_id` mediumint(9) NOT NULL,
  `category_id` smallint(9) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

set @n=3, @i=0, @p=0;
 
select * from (select *, if (@p=x, @i:=@i+1,(@i:=0) or (@p:=x)) and (@i<@n) AS f from g t1 join p t2 on t1.x=t2.y) xx where f;