php 如何准确地使用 onDelete = "SET NULL" - Doctrine2
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How exactly to use onDelete = "SET NULL" - Doctrine2
提问by Faery
I have a class Categorycontaining this:
我有一个包含这个的类Category：
/**
* @ORM\OneToMany(targetEntity="Friend", mappedBy="category")
* @ORM\OrderBy({"name" = "ASC"})
*/
protected $friends;
and a class Friendwith this:
和一个班级的朋友：
/**
* @ORM\ManyToOne(targetEntity="Category", inversedBy="friends")
* @ORM\JoinColumn(name="category_id", referencedColumnName="id", onDelete="SET NULL")
*/
protected $category;
What I want is to be able to delete categories no matter if there are some friends from this category, and if there are - the category field for this friends to be set to NULL.
我想要的是能够删除类别，无论是否有来自该类别的一些朋友，如果有 - 此朋友的类别字段设置为NULL。
I tried to put onDelete="CASCADE"to the ManyToOne annotation, then to the OneToMany, I tried what is shown above, I tried using cascade={"remove"}in the OneToMany annotation, and nothing worked! I couldn't find a example as well. Could you please help me?
我尝试放入onDelete="CASCADE"ManyToOne 注释，然后放入OneToMany，我尝试了上面显示的内容，我尝试cascade={"remove"}在 OneToMany 注释中使用，但没有任何效果！我也找不到例子。请你帮助我好吗？
回答by Zeljko
This must be a crazy answer but did you update database schema? onDelete="SET NULL"is on database level, it must work on innoDB.
这一定是一个疯狂的答案，但您是否更新了数据库架构？onDelete="SET NULL"在数据库级别，它必须在 innoDB 上工作。
