/**
* Filter the query by a related Post object
*
* @param Post $post the related object to use as filter
* @param string $comparison Operator to use for the column comparison, defaults to Criteria::EQUAL
*
* @return CategoryQuery The current query, for fluid interface
*/
public function filterByPost($post, $comparison = null)
{
if ($post instanceof Post) {
return $this->addUsingAlias(CategoryPeer::ID, $post->getCategoryId(), $comparison);
} elseif ($post instanceof PropelCollection) {
return $this->usePostQuery()->filterByPrimaryKeys($post->getPrimaryKeys())->endUse();
} else {
throw new PropelException('filterByPost() only accepts arguments of type Post or PropelCollection');
}
}