$sth=eval{$self->db->prepare("UPDATE `participants` SET `peer_id`=?,`role`=? WHERE `participant`=? AND `id` IN (SELECT `id` FROM `rooms` WHERE `name`=?)")}||returnundef;
$sth=eval{$self->db->prepare("UPDATE `participants` SET `peer_id`=?,`role`=? WHERE `participant`=? AND `id` IN (SELECT `id` FROM `rooms` WHERE `name`=?)")}||returnundef;