public static function removeRole($role)
{
if ($role instanceof Role) {
$role = $role->id;
}
$db = self::getConnection();
$platform = $db->getDatabasePlatform();
return $db->executeUpdate('UPDATE ' . self::getMetadata()->getTable() . ' SET roles = NULLIF(' . $platform->getTrimExpression("REPLACE (" . $platform->getConcatExpression($db->quote(','), 'roles', $db->quote(',')) . ", ',{$role},', ',')", 3, $db->quote(',')) . ", '')");
}