Error Number: 2006

MySQL server has gone away

SELECT `a`.`hits`, `b`.`title`, `b`.`url`, `b`.`category`, `b`.`image_headline`, `c`.`category_url` FROM (`dbhits` a) LEFT JOIN `dbnews` b ON `a`.`related_id` = `b`.`idnews` INNER JOIN `dbcategory` c ON `b`.`category` = `c`.`category_id` WHERE `a`.`group` = 'news' AND `b`.`level` = '1' AND DATE(b.schedule) >= '2019-11-17' ORDER BY `a`.`hits` DESC LIMIT 5