Fatal error: Uncaught mysqli_sql_exception: Cannot delete or update a parent row: a foreign key constraint fails (`apexlaw_college`.`feesmaster`, CONSTRAINT `feesmaster_ibfk_3` FOREIGN KEY (`head_id`) REFERENCES `headmaster` (`id`)) in /home/apexcollege/public_html/demo/head_master.php:30 Stack trace: #0 /home/apexcollege/public_html/demo/head_master.php(30): mysqli->query('DELETE FROM hea...') #1 {main} thrown in /home/apexcollege/public_html/demo/head_master.php on line 30