/**
* Removes the result of query from this query.
*
* @param DataQuery $subtractQuery
* @param string $field
* @return $this
*/
public function subtract(DataQuery $subtractQuery, $field = 'ID')
{
$fieldExpression = $subtractQuery->expressionForField($field);
$subSelect = $subtractQuery->getFinalisedQuery();
$subSelect->setSelect(array());
$subSelect->selectField($fieldExpression, $field);
$subSelect->setOrderBy(null);
$subSelectSQL = $subSelect->sql($subSelectParameters);
$this->where(array($this->expressionForField($field) . " NOT IN ({$subSelectSQL})" => $subSelectParameters));
return $this;
}