/** * Filter the query by a related \Author object * * @param \Author|ObjectCollection $author The related object(s) to use as filter * @param string $comparison Operator to use for the column comparison, defaults to Criteria::EQUAL * * @throws \Propel\Runtime\Exception\PropelException * * @return ChildBookQuery The current query, for fluid interface */ public function filterByAuthor($author, $comparison = null) { if ($author instanceof \Author) { return $this->addUsingAlias(BookTableMap::COL_AUTHOR_ID, $author->getId(), $comparison); } elseif ($author instanceof ObjectCollection) { if (null === $comparison) { $comparison = Criteria::IN; } return $this->addUsingAlias(BookTableMap::COL_AUTHOR_ID, $author->toKeyValue('PrimaryKey', 'Id'), $comparison); } else { throw new PropelException('filterByAuthor() only accepts arguments of type \\Author or Collection'); } }