问题描述
一个 User 有一个 Package 与之关联.许多用户可以参考同一个包.User 不能在没有定义 Package 的情况下存在.User 应该拥有该关系.关系是双向的，因此 Package 中包含零个或多个用户.
An User has one Package associated with it. Many users can refer to the same package. User cannot exists without a Package defined. User should own the relation. Relation is bidirectional, so a Package has zero or more users in it.
这些要求导致 User 的 ManyToOne 关系和 Doctrine 2 中 Package 的 OneToMany 关系.但是 <user 表(即外键)中的 code>package_id 允许 null 值.我试过设置 nullable=false 但命令:
These requirements lead to ManyToOne relation for User and OneToMany relation of Package in Doctrine 2. However package_id in user table (that is foreign-key) allows null values. I've tried setting nullable=false but command:
php app/console doctrine:generate:entities DL --path="src" --no-backup
表示关系 ManyToOne 没有属性 nullable.我缺少什么?
Says that there is no attribute nullable for the relation ManyToOne. What i'm missing?
class User
{
/**
* @ORMId
* @ORMColumn(type="integer")
* @ORMGeneratedValue(strategy="AUTO")
*/
private $id;
/**
* @ORMManyToOne(targetEntity="Package", inversedBy="users")
*/
private $package;
}
class Package
{
/**
* @ORMId
* @ORMColumn(type="integer")
* @ORMGeneratedValue(strategy="AUTO")
*/
private $id;
/**
* @ORMOneToMany(targetEntity="User", mappedBy="package")
*/
private $users;
}
推荐答案
在多对一关系上使用 JoinColumn 注释:
Use the JoinColumn annotation on your ManyToOne relation:
/**
* @ORMManyToOne(targetEntity="Package", inversedBy="users")
* @ORMJoinColumn(name="package_id", referencedColumnName="id", nullable=false)
*/
private $package;
ManyToOne 本身不能为空，因为它与特定列无关.另一方面，JoinColumn 标识数据库中的列.因此，您可以使用普通"属性，例如可为空或唯一性！
The ManyToOne itself cannot be nullable, because it doesn't relate to a specific column. The JoinColumn on the other hand identifies the column in the database. Thus, you can use "normal" attributes like nullable or unique!
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