按条令1.2中的生成字段排序

我正在使用predqlselect()回调添加“虚拟字段”。但是,必须在回调被激发之前对查询进行验证,因为在查询该模型时,无法按该新字段排序。

这是我的回拨:

class Artist extends BaseArtist
{
    public function preDqlSelect(Doctrine_Event $event)
    {

        // Add title field (concatenation of first_name, last_name, and company fields)
        $params = $event->getParams();
        $q = $event->getQuery();
        $a = $params['alias'];
        if (
        $q->contains($a.'.first_name')
        && $q->contains($a.'.last_name')
        && $q->contains($a.'.company')
        ) {
            $exists = '!ISNULL(NULLIF('.$a.'.%s, \'\'))';
            $value = 'IFNULL('.$a.'.%1$s, \'\')';
            $if = sprintf($exists, 'first_name').' OR '.sprintf($exists, 'last_name');
            $thenPiece1 = sprintf($value, 'first_name').', \' \', '.sprintf($value, 'last_name');
            $thenPiece2 = 'IF('.sprintf($exists, 'company').', CONCAT(\' (\', '.sprintf($value, 'company').', \')\'), \'\')';
            $then = 'TRIM(CONCAT('.$thenPiece1.', '.$thenPiece2 .'))';
            $else = sprintf($value, 'company');
            $select = 'IF('.$if.', '.$then.', '.$else.') AS title';
            $q->addSelect($select);
        }
    }
// ...

我的问题是:

$artists = Doctrine_Query::create()
    ->select('a.id, a.first_name, a.last_name, a.company')
    ->from('Artist a')
    ->innerJoin('a.Products p')
    ->where('a.active <> 0')
    ->andWhere('p.active <> 0')
    ->orderBy('a.title')
    ->execute();

以下是我得到的错误:

致命错误:未捕获的异常'distric_query_exception'(消息'unknown column title'在/[删除]/lib/distric/distric/query/orderby.php:94堆栈跟踪:0/[删除]/lib/distric/query/abstract.php(2077):distric_query_orderby->parse('a.title')1/[删除]/lib/distric/distric/query.php(1160):distric_query_abstract->_processdqlquerypart('orderby',array)2/[removed]/lib/distric/distric/query.php(1126):distric诳query->buildsqlquery(false)诳3/[removed]/lib/distric/query/abstract.php(1137):distric诳query->getsqlquery(array,false)诳4/[removed]/lib/distric/distric/query/abstract.php(1106):distric组件(数组)5/[已删除]/lib/distric/distric/query/abstract.php(1001):distric query abstract->prequery(array)6/srv/web/museumfounda in/[已删除]/lib/distric/query/orderby.php,第94行