Выдает такую хрень при попытке написать коммент

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '2015-06-16 15:32:40'' at line 3. Failing Query: "INSERT INTO `personal_discussion` (`post_id`,`user_id` , `last_time`) VALUES ('2031108', '246393', '2015-06-16 15:32:40'') ON DUPLICATE KEY UPDATE `last_time` = '2015-06-16 15:32:40' "