现存Article
,Category
两个entity,关系为onetomany;
其中article不是必须对应category,如果article不存在对应的分类,那么category_id =0;
那么问题来了
$article = new Article();
$article->setTitle('This is a test article');
//...
$em->persist($article);
$em->flush();
报错如下,category_id 不能为空
[Doctrine\DBAL\Driver\PDOException]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'category_id' cannot be null
[PDOException]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'category_id' cannot be null
这种非必须的Association怎么设置呢
把 Article::$category 的 nullable 属性设为 true 就可以了
``
class Article
{
}
``