Fatal error: Uncaught PDOException: SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`user128`.`course_and_teacher`, CONSTRAINT `fk_teacher` FOREIGN KEY (`id_of_teacher`) REFERENCES `teacher` (`id`)) in /home/user128/public_html/laba2/index_01.php:77 Stack trace: #0 /home/user128/public_html/laba2/index_01.php(77): PDOStatement->execute() #1 {main} thrown in /home/user128/public_html/laba2/index_01.php on line 77