My delete button actually doesn't delete anything ,, when i click on it it does nothing

Question

<?php

$query = "select courses.id, courses.title, courses.category_id, courses.description, courses.start_date, courses.end_date, courses.image, courses.location, courses.published, course_category.title as category, trainers.name as trainer from courses 
LEFT JOIN course_category ON courses.category_id = course_category.id
LEFT JOIN trainers ON courses.trainer_id = trainers.id
order by courses.id DESC";

$courses = $traininovate->fetchAllData($query, $con);

if (isset($_GET['delete'])) {
    $course_id = $_GET['delete']; // course id 

    $query = "DELETE FROM COURSES WHERE id = $course_id";
    $traininovate->deleteRow($query, $con);

    $query = "DELETE FROM open_attendance WHERE course_id = $course_id";
    $traininovate->deleteRow($query, $con);

    $query = "DELETE FROM course_materials WHERE course_id = $course_id";
    $traininovate->deleteRow($query, $con);

    $query = "DELETE FROM course_attendance WHERE course_id = $course_id";
    $traininovate->deleteRow($query, $con);

    $query = "DELETE FROM course_evaluation WHERE course_id = $course_id";
    $traininovate->deleteRow($query, $con); 

    header("location: courseslist.php");
}
?>