/**
  * @param Column $column
  * @return string
  */
 private function getPrefixedField(Column $column)
 {
     if ($column instanceof EntitiesCountColumn) {
         return $column->getField() . '_count';
     } elseif ($column instanceof EntitiesScalarColumn) {
         return $column->getField() . '_' . $column->getOperation();
     } elseif ($column instanceof EntityColumn) {
         return $column->getEntityPrefix() . '.' . $column->getEntityField();
     }
     return $this->table->getPrefix() . '.' . $column->getField();
 }