$sql = $con->prepare("SELECT * FROM students WHERE stud_id = (a)   ");

$id = (a)   ['student_id'] ?? null;

header("Location: index.php") (a)  

$stmt->execute([":id" _____ $id]);$sql_____execute([":id" => $id]);

(a)  

$con->setAttribute( (a)   ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

} catch (PDOException $e (a)   {

$insert = "INSERT INTO students (stud_fname, stud_mname, stud_lname, stud_email, stud_password) VALUES (:stud_fname,:stud_mname,:stud_lname,:stud_email,:stud_pass)" (a)  

$stmt->execute([" (a)   " => $id]);

$stmt = $con (a)   prepare($sql);

header("Location index.php");

(a)  

$sql = "DELETE FROM students WHERE stud_id = :id" (a)  

$stmt = $con (a)   prepare($insert);

$id = (a)   ['student_id'] ?? null;

while($data = $sql->fetch( (a)   FETCH_ASSOC)) {

header("Location: notfound.php") (a)  

$sql = $con (a)   query("SELECT * FROM students");

$row = $sql->fetch( (a)   FETCH_ASSOC);

header("Location: index.php") (a)  

$stmt = $con (a)   prepare($update);