Trouble with upgrade

I run /wp-admin/upgrade.php

Error:
Fatal error: Cannot use object of type stdClass as array in /app/home/vorchun/wp-admin/upgrade-functions.php on line 705

Code in upgrade-functions.php:

$query = "DESCRIBE ".$tableusers." user_pass";
$res = $wpdb->get_results($query);
if ($res[0]["Type"] != "varchar(32)") {
$wpdb->query("ALTER TABLE ".$tableusers." MODIFY user_pass varchar(64) not null");
}
$query = "SELECT ID, user_pass from ".$tableusers;
foreach ($wpdb->get_results($query) as $row) {
if (!preg_match("/^[A-Fa-f0-9]{32}$/", $row->user_pass)) {
$wpdb->query("UPDATE ".$tableusers." SET user_pass = MD5("".$row->user_pass."") WHERE ID = "".$row->ID.""");
}
}


Help me!