Doctrine 2 OneToMany Cascade SET NULL

Question

错误

无法删除或更新父行:外键约束失败.

课程

class Teacher {

    /**
     *@ORM\OneToMany(targetEntity="publication", mappedBy="teacher")
     */
    protected $publications;
}

class Publication {

    /**
     * @ORM\ManyToOne(targetEntity="Teacher", inversedBy="publications")
     * @ORM\JoinColumn(name="teacher_id", referencedColumnName="id")
     */
    protected $teacher;
}

我想要

我想要的是,当你删除教师时,id_teacher被修改为NULL.我想保留出版物但不参考教授.

我不知道在Doctrine中是怎么做的,这可能吗？或者总是与老师的关系？

Answer 1

您应该onDelete="SET NULL"在实体的注释中添加选项,如下所示:

class Publication
{
    /**
    * @ORM\ManyToOne(targetEntity="Teacher", inversedBy="publications")
    * @ORM\JoinColumn(name="teacher_id", referencedColumnName="id", onDelete="SET NULL")
    */
    protected $teacher;
}

干杯!

Answer 2

对于 Symfony 6 (PHP 8)（引擎“InnoDB”）

#[ORM\JoinColumn(nullable: true, onDelete: 'SET NULL')]