php 原则 2 - 多对一关系的外键不允许空值
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Doctrine 2 - Disallow null value on foreign keys of ManyToOne relationships
提问by Tobias Gies
I have a ManyToOne relationship in one of my entities, like so:
我在我的一个实体中有一个 ManyToOne 关系，如下所示：
class License {
// ...
/**
* Customer who owns the license
*
* @var \ISE\LicenseManagerBundle\Entity\Customer
* @ORM\ManyToOne(targetEntity="Customer", inversedBy="licenses")
* @ORM\JoinColumn(name="customer_id", referencedColumnName="id")
*/
private $customer;
// ...
}
class Customer {
// ...
/**
* Licenses that were at one point generated for the customer
*
* @var \Doctrine\Common\Collections\ArrayCollection
* @ORM\OneToMany(targetEntity="License", mappedBy="customer")
*/
private $licenses;
// ...
}
This generates a database schema where the "customer_id" field of the license table is allowed to be null, which is exactly what I do not want.
这会生成一个数据库架构，其中许可表的“customer_id”字段允许为空，这正是我不想要的。
Here's some code where I create a record to prove that it indeed allows null values for the reference fields:
这是我创建记录以证明它确实允许引用字段为空值的一些代码：
$em = $this->get('doctrine')->getEntityManager();
$license = new License();
// Set some fields - not the reference fields though
$license->setValidUntil(new \DateTime("2012-12-31"));
$license->setCreatedAt(new \DateTime());
// Persist the object
$em->persist($license);
$em->flush();
Basically, I don't want a License to be persisted without having a Customer assigned to it. Is there some annotation that needs to be set or should I just require a Customer object to be passed to my License's constructor?
基本上，我不希望在没有客户分配给它的情况下保留许可证。是否需要设置一些注释，或者我应该只需要将 Customer 对象传递给我的许可证的构造函数？
The database engine I use is MySQL v5.1, and I am using Doctrine 2 in a Symfony2 application.
我使用的数据库引擎是 MySQL v5.1，我在 Symfony2 应用程序中使用 Doctrine 2。
回答by zim32
Add nullable = falseto the JoinColumnannotation:
添加nullable = false到JoinColumn注释中：
@ORM\JoinColumn(..., nullable=false)
回答by Rafael Barros
Just posting because @zim32 didn't tell where we should put the statement, so i had to make a trial and error.
只是发帖是因为@zim32 没有告诉我们应该把声明放在哪里，所以我不得不反复试验。
Yaml:
亚姆：
manyToOne:
{field}:
targetEntity: {Entity}
joinColumn:
name: {field}
nullable: false
referencedColumnName: {id}
cascade: ['persist']
回答by Stanzi1791
I couldn't find an XMLexample of how to do this, so I'm going to leave this snippet here in case anyone else is looking for this:
我找不到有关如何执行此操作的XML示例，因此我将保留此代码段，以防其他人正在寻找此代码：
<many-to-one field="author" target-entity="User">
<join-column name="author_id" referenced-column-name="id" nullable="false" />
</many-to-one>
The nameand referenced-column-nameare required, see the docs: https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/xml-mapping.html#join-column-element
该名称和引用的列名称是必需的，请参阅该文档：https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/xml-mapping.html#join-column-element
