如何将PHP imagecopymerge函数创建的图像存储在mysql数据库中

Error Number: 1064</p><p>You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'id #48 WHERE `id` = \'5\'\' at line 1
UPDATE `users_thumbnails` SET `thumbnail` = Resource id #48 WHERE `id` = \'5\'    

$base = imagecreatefromjpeg(\'application/assets/images/vel1_bg.jpg\');
    foreach($array as $key => $value){
                $item = imagecreatefrompng(\'application/assets/images/items/item\' . $value[0] . \'.png\');
                list($width, $height, $type, $attr) = getimagesize(\'application/assets/images/items/item\'. $value[0] . \'.png\');
                imagecopymerge($base, 
                            $item,
                            $value[1],
                            $value[2],
                            0,
                            0,
                            $width,
                            $height,
                            100);
                //imagedestroy($item);
            }

    $data = array(\'thumbnail\' => $base);
    $this->db->where(\'fbid\', $this->session->userdata(\'id\'));
    $this->db->update(\'users_thumbnails\', $data);