public function getColumn($name)
    {
        if ($name instanceof AnDomainResourceColumn) {
            return $name;
        }

        if (strpos($name, '.') !== false) {
            $parts = explode('.', $name, 2);
            $name = $parts[1];
            foreach ($this->_resources as $resource) {
                if ($resource->getAlias() == $parts[0]) {
                    break;
                }
            }
            $resources = array($resource);
        } else {
            $resources = $this->_resources;
        }

        foreach ($resources as $resource) {
            if ($resource->hasColumn($name)) {
                return $resource->getColumn($name);
            }
        }

        //throw new AnException('Column '.$name.' doesn\'t exists');
    }