$stm = $db->dbStream->prepare(" INSERT INTO `groups_cover` (coverPositions, group_id, screen_name, title, photo, owner_id, grid_mobile, timezone, token_group, server_id, type_render, type_reload_cover, cover_morning_bg)
SELECT coverPositions, group_id, screen_name, title, photo, owner_id, grid_mobile, timezone, token_group, server_id, type_render, type_reload_cover, cover_morning_bg FROM `groups_cover`
WHERE `group_id` = ? AND `id` = ?");
$stm->bindValue(1, $_GET['group_id'], PDO::PARAM_INT);
$stm->bindValue(2, $_GET['id_cover'], PDO::PARAM_INT);
try {
$stm->execute();
$lastid = $db->dbStream->lastInsertId();
} catch (PDOException $error) {
trigger_error("Ошибка при работе с базой данных: {$error}");
}
var_dump($lastid);
Var_dump(file_exist(ваш путь)) что отдаёт?