如何使用onDelete =“SET NULL” - 教义2 [英] How exactly to use onDelete = "SET NULL" - Doctrine2

问题描述

我有一个类类别，包含以下内容：

I have a class Category containing this:

/**
 * @ORM\OneToMany(targetEntity="Friend", mappedBy="category")
 * @ORM\OrderBy({"name" = "ASC"})
 */
protected $friends;

和一个类朋友：

 /**
 * @ORM\ManyToOne(targetEntity="Category", inversedBy="friends")
 * @ORM\JoinColumn(name="category_id", referencedColumnName="id",  onDelete="SET NULL")
 */
protected $category;

我想要的是删除类别，无论是否有这个类别的朋友，如果有 - 这个朋友的类别字段被设置为NULL。

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.

我试图把 onDelete =CASCADE到ManyToOne注释，然后到OneToMany，我尝试了上面显示的内容，我尝试在OneToMany注释中使用 cascade = {remove} ，没有任何工作！我也找不到一个例子。你可以帮助我吗？

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?

推荐答案

这必须是一个疯狂的答案，但是你更新了数据库模式？ onDelete =SET NULL在数据库级别，它必须适用于innoDB。

This must be a crazy answer but did you update database schema? onDelete="SET NULL" is on database level, it must work on innoDB.

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