/**
* Filter the query by a related Book object
*
* @param Book|PropelCollection $book The related object(s) to use as filter
* @param string $comparison Operator to use for the column comparison, defaults to Criteria::EQUAL
*
* @return ItemQuery The current query, for fluid interface
*/
public function filterByBook($book, $comparison = null)
{
if ($book instanceof Book) {
return $this->addUsingAlias(ItemPeer::ISBN, $book->getIsbn(), $comparison);
} elseif ($book instanceof PropelCollection) {
if (null === $comparison) {
$comparison = Criteria::IN;
}
return $this->addUsingAlias(ItemPeer::ISBN, $book->toKeyValue('PrimaryKey', 'Isbn'), $comparison);
} else {
throw new PropelException('filterByBook() only accepts arguments of type Book or PropelCollection');
}
}
