Как сделать выборку из mysql в моем случае?
SELECT `ui`.`id` AS `image_id`,
       `ui`.`user_id` AS `user_id`, 
       `ui`.`create_date` AS `image_create_date`,
       `ui`.`name` AS `image_name`,
       `ui`.`title` AS `image_title`,
       `ui`.`descr` AS `image_descr`,
       `ui`.`views` AS `image_views`,
       `ui`.`plus` AS `image_plus`,
       `ui`.`minus` AS `image_minus`,
       `bu`.`first_name` AS `user_first_name`,
       `bu`.`last_name` AS `user_last_name`,
       `bu`.`photo` AS `user_photo`,
       COUNT(`c`.`id`) AS  `com_cnt`
    FROM `user_images` AS `ui`
    LEFT JOIN `bpl_users` AS `bu` ON `bu`.`id` = `ui`.`user_id`
    LEFT JOIN `comments` AS `c` ON `c`.`image_id` = `ui`.`id`
    GROUP BY `ui`.`id`
    ORDER BY `ui`.`create_date` DESC LIMIT 9
и добавтье в схему индексCREATE INDEX `image_id_idx` ON `comments` (`image_id`);
Может так SELECT 
user_images.id AS image_id, user_images.user_id AS user_id,
user_images.create_date AS image_create_date, user_images.name AS image_name,
user_images.title AS image_title, user_images.descr AS image_descr,
user_images.views AS image_views, user_images.plus AS image_plus,
user_images.minus AS image_minus,
bpl_users.first_name AS user_first_name, bpl_users.last_name AS user_last_name,
bpl_users.photo AS user_photo,
(SELECT COUNT(*) FROM `comments` WHERE `image_id`=`user_images`.`id` ) AS quantity_comments

FROM `user_images` INNER JOIN `bpl_users`
ON `user_images`.`user_id`=`bpl_users`.`id`
ORDER BY `user_images`.`create_date` DESC LIMIT 9