running into errors in trying to get this php form from when the user clicks the delete button it deletes the subjects from the list

when i hit the delete button it goes to Invalid subject ID. page . and when i try to add something to a list it shows Invalid category data. Check all fields and try again.i feel like i almost have it i just need an extra eye on it .

this is the code i have Subject_list.php:

// Get all subjects $query = 'SELECT * FROM subjects ORDER BY subjectID'; $statement = $db->prepare($query); $statement->execute(); $subjects = $statement->fetchAll(); $statement->closeCursor(); ?>

Course Manager

Subject List

Name

Add Subject

Name

List Courses

© Thomas University, Inc.

Here is the delete_subject.php code:

// Validate inputs if ($subjectName == null || $subjectName== false) { $error = "Invalid subject ID."; include('error.php'); } else { require_once('database1.php');

// Add the book to the database $query = 'DELETE FROM subjects WHERE subjectID = :subject_id'; $statement = $db->prepare($query); $statement->bindValue(':subject_list', $subjectName); $statement->execute(); $statement->closeCursor();

// Display the subject List page include('subject_list.php'); } ?>

Now on the bottom of the form i need when the user clicks the Add button it adds another subject to the list :

my Add_subject.php code:

// Validate inputs if ($subject == null) { $error = "Invalid category data. Check all fields and try again."; include('error.php'); } else { require_once('database1.php');

// Add the subject to the database $query = "INSERT INTO subjects (subjectName) VALUES (:subject)"; $statement = $db->prepare($query); $statement->bindValue(':subject_list', $subjectName); $statement->execute(); $statement->closeCursor();

// Display the Category List page include('subject_list.php'); } ?>

Database1.php code:

$dsn = 'mysql:host=localhost;dbname=my_courses';

$username = 'mgs_user';

$password = 'pa55word';

try {

$db = new PDO($dsn, $username, $password);

} catch (PDOException $e) {

$error_message = $e->getMessage();

include('database_error.php');

exit();

}

?>

Course Manager Subject List Name Computer Info Systems Delete English American LiteratureDelete American History Music World History Delete Delete Delete Delete Add Subject Name PHP Add List Courses