Fatal error: Uncaught PDOException: SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`ujjainto_vupharma`.`marks`, CONSTRAINT `fk_marks_subject` FOREIGN KEY (`subject_code`) REFERENCES `subjects` (`code`)) in /home/ujjainto/vu.cstf.in/admin/view_subjects.php:17 Stack trace: #0 /home/ujjainto/vu.cstf.in/admin/view_subjects.php(17): PDOStatement->execute(Array) #1 {main} thrown in /home/ujjainto/vu.cstf.in/admin/view_subjects.php on line 17