ethics-canvas/canvas/php/add-owner-to-collaborators.php

<?php
    require_once("../../php/db_utils.php");
    
    try {
        // Declarations
        $ownerExists = false;
        
        // Connect to the database
        $database = db_connect();
        
        // Incoming data
        $canvasId = $_POST["canvas_id"];
        
        // Check if the collaborator is a member
        $query = 'SELECT collaborator
                  FROM collaborators
                  WHERE canvas_id = "' . $canvasId . '"
                  AND collaborator = (SELECT canvas.user_id
                                      FROM collaborators
                                      INNER JOIN canvas ON canvas.canvas_id = collaborators.canvas_id
                                      AND canvas.canvas_id = "' . $canvasId . '"
                                      LIMIT 1);';
                                        
        $recordSet = db_query_return($database, $query);
        
        $record = mysqli_fetch_assoc($recordSet);
        
        if(isset($record["collaborator"])) {
            $ownerExists = true;
        }
        
        // If the owner does not already exist
        if($ownerExists == false) {
            // Add owner
            $query = 'INSERT INTO collaborators (canvas_id, collaborator)
                      VALUES ("' . $canvasId . '",
                             (SELECT user_id
                              FROM canvas
                              WHERE canvas_id = "' . $canvasId . '"
                              LIMIT 1));';
                                
            // Insert new or update old description
            db_query_no_return($database, $query);
        }
        
        // Close the connection to the database
        db_close($database);
    }
    catch(Exception $e) {
        $errorMsg = $e->getMessage();
        print_r($errorMsg);
    }
?>