Unable to execute insert statement while saving in symfony (propel) form with map list - forms

Question

In doSave() function in form I'm trying to save article category (which it is a node in a tree), and then assign to this category articles (many to many relationship).
I'm getting an error while in $this->saveWaArticleNewsCategoryMapList($con); line. (Project is builded on symfony 1.4.16). There is no error when I assign article to an existing category.
public function doSave($con = null) {
$scope = $this->getValue('tree_scope');
$toEdit = $this->getObject();
if ($toEdit->isNew()) {
$node = new ArticleCategory();
$node->setBrandId($this->getValue('brand_id'));
$node->setName($this->getValue('name'));
$node->setTreeScope($scope);
$root = ArticleCategoryQuery::create()->findRoot($scope);
if ($root == null) {
$root = new ArticleCategory();
$root->setName('Root');
$root->setTreeScopeIdValue($scope);
$root->makeRoot();
$root->save($con);
$node->insertAsLastChildOf($root);
$node->save($con);
return;
}
$parent = ArticleCategoryQuery::create()->findPk($this->getValue('parent_id'));
$node->insertAsLastChildOf($parent);
} else {
$node = ArticleCategoryQuery::create()->findOneByArticleCategoryId($toEdit->getArticleCategoryId());
$node->setBrandId($this->getValue('brand_id'));
$node->setName($this->getValue('name'));
if ($toEdit->getParent()->getArticleCategoryId() != $this->getValue('parent_id')) {
$parent = ArticleCategoryQuery::create()->findPk($this->getValue('parent_id'));
$node->moveToLastChildOf($parent);
}
}
$node->save($con);
$this->saveArticleNewsCategoryMapList($con); <--Error
$this->saveArticleHelpCategoryMapList($con);
}
Error:
Unable to execute INSERT statement [INSERT INTO `article_news_category_map` (`ARTICLE_ID`) VALUES (:p0)] [wrapped: SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`projectname`.`article_news_category_map`, CONSTRAINT `article_news_category_map_FK_2` FOREIGN KEY (`category_id`) REFERENCES `article_category` (`article_category_id`) ON DELETE CASCADE)]

Answer 1

Updating ArticleCategoryId in object solved the problem:
$node->save($con);
$this->getObject()->setArticleCategoryId($node->getArticleCategoryId());
...