Fatal error: Uncaught mysqli_sql_exception: Cannot delete or update a parent row: a foreign key constraint fails (`kjry223ict301`.`courses`, CONSTRAINT `courses_ibfk_1` FOREIGN KEY (`department_id`) REFERENCES `departments` (`department_id`)) in /var/www/html/ict301/201/kjry223/finalcode/manage.php:28 Stack trace: #0 /var/www/html/ict301/201/kjry223/finalcode/manage.php(28): mysqli_query() #1 {main} thrown in /var/www/html/ict301/201/kjry223/finalcode/manage.php on line 28