public function load(QueryBuilder $query, ClassMetadata $metadata)
{
$field = $this->mapping['fieldname'];
$boltname = $metadata->getBoltName();
$from = $query->getQueryPart('from');
if (isset($from[0]['alias'])) {
$alias = $from[0]['alias'];
} else {
$alias = $from[0]['table'];
}
$dummy = 'f_' . $field;
$query->addSelect($this->getPlatformGroupConcat($field, $query))->leftJoin($alias, $this->mapping['tables']['field_value'], $dummy, $dummy . ".content_id = {$alias}.id AND " . $dummy . ".contenttype='{$boltname}' AND " . $dummy . ".name = '{$field}'");
}