function find_selected_study() { global $current_study; if (isset($_GET["study"])) { $current_study = find_study_by_id($_GET["study"]); } else { $current_study = null; } }
<?php require_once "../includes/session.php"; require_once "../includes/db_connection.php"; require_once "../includes/functions.php"; ?> <?php confirm_logged_in(); ?> <?php $current_study = find_study_by_id($_GET["study"]); if (!$current_study) { // Subject ID was missing or invalid or // subject couldn't be found in database redirect_to("manage_content.php"); } $study_id = $current_study["study_id"]; $query = "DELETE FROM studies "; $query .= "WHERE study_id = {$study_id} "; $query .= "LIMIT 1"; $result = mysqli_query($connection, $query); if ($result && mysqli_affected_rows($connection) >= 0) { $_SESSION["message"] = "Study deleted"; redirect_to("manage_studies.php"); } else { $_SESSION["message"] = "Study deletion failed"; redirect_to("manage_studies.php?study={$study_id}"); }