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 '' at line 1

URL: /index.php

MySQL Query: UPDATE `site_site` SET `visit_data`='{"date":"20190818","today":1,"total":1}' WHERE id=

MySQL Errno: 1064

MySQL Error: 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 '' at line 1