src/orm/classes/Field/Bindings.php
public function onSelect(ezcQuerySelect $query, array $currentSelects)
    {
        $bindingsTable = $this->getBindingsTable();
        $currentSelects []= $bindingsTable->getName() . '.' . $this->name;
        $query->groupBy($this->table->getName(). '.' . $this->table->getPrimaryKey());
        return $currentSelects;
    }
public function onSelect(ezcQuerySelect $query, array $currentSelects)
    {
        $bindingsTable = $this->getBindingsTable();
        $currentSelects []= $bindingsTable->getName() . '.' . $this->name;
        $query->groupBy($this->table->getName(). '.' . $this->table->getPrimaryKey());
        return $currentSelects;
    }
Дополнительные действия при формировании раздела SELECT

@param ezcQuerySelect $query
@param array          $currentSelects  уже сформированные части SELECT

@return array  изменённый $currentSelects