symfony - Doctrine 2 模式更新产生 MySQL errno 150，外键约束

Question

在 Symfony2 中使用 Doctrine ORM 时，我从三个不同的实体生成了以下表格，其中accessory有两个外键约束（下面标记为 A 和 B）。

describe publication;
+-------------------+--------------+------+-----+---------+----------------+
| Field             | Type         | Null | Key | Default | Extra          |
+-------------------+--------------+------+-----+---------+----------------+
| id                | int(11)      | NO   | PRI | NULL    | auto_increment |
| kid               | varchar(10)  | NO   |     | NULL    |                |
| title             | varchar(255) | NO   |     | NULL    |                |
| title_canonical   | varchar(255) | NO   |     | NULL    |                | <- A
| created           | datetime     | NO   |     | NULL    |                |
| modified          | datetime     | NO   |     | NULL    |                |
+-------------------+--------------+------+-----+---------+----------------+

describe accessory;
+-------------------+--------------+------+-----+---------+----------------+
| Field             | Type         | Null | Key | Default | Extra          |
+-------------------+--------------+------+-----+---------+----------------+
| id                | int(11)      | NO   | PRI | NULL    | auto_increment |
| publication_title | varchar(255) | YES  |     | NULL    |                | <- A
| index_id          | int(11)      | NO   |     | NULL    |                |
| index_alias       | varchar(255) | NO   |     | NULL    |                |
| value             | longtext     | NO   |     | NULL    |                |
| attribute_name    | varchar(255) | YES  |     | NULL    |                | <- B
+-------------------+--------------+------+-----+---------+----------------+

describe attribute;
+-------------------+--------------+------+-----+---------+----------------+
| Field             | Type         | Null | Key | Default | Extra          |
+-------------------+--------------+------+-----+---------+----------------+
| id                | int(11)      | NO   | PRI | NULL    | auto_increment |
| name              | varchar(255) | NO   |     | NULL    |                |
| name_canonical    | varchar(255) | NO   |     | NULL    |                | <- B
| parameter         | varchar(16)  | NO   |     | NULL    |                |
+-------------------+--------------+------+-----+---------+----------------+

外键使用注释映射：

发布.php

/**
 * @ORM\OneToMany(targetEntity="Accessory", mappedBy="publication")
 */
protected $accessories;

附件.php

/**
 * @ORM\ManyToOne(targetEntity="Publication", inversedBy="accessories")
 * @ORM\JoinColumn(name="publication_title", referencedColumnName="title_canonical")
 */
protected $publication;


/**
 * @ORM\ManyToOne(targetEntity="Attribute", inversedBy="accessories")
 * @ORM\JoinColumn(name="attribute_name", referencedColumnName="name_canonical")
 */
protected $attribute;

属性.php

/**
 * @ORM\OneToMany(targetEntity="Accessory", mappedBy="attribute")
 */
protected $accessories;

但是在运行时php app/console doctrine:schema:update --force我得到了这个异常

[Doctrine\DBAL\DBALException]                                                                                                                                               
An exception occurred while executing 'ALTER TABLE accessory ADD CONSTRAINT FK_A1B1251CCEE83EE7 FOREIGN KEY (publication_title) REFERENCES publication (title_canonical)':  

SQLSTATE[HY000]: General error: 1005 Can't create table 'publicationsapp.#sql-2a3c_2828' (errno: 150)

所以我跑了php app/console doctrine:schema:update --dump-sql

ALTER TABLE accessory ADD CONSTRAINT FK_A1B1251CCEE83EE7 FOREIGN KEY (publication_title) REFERENCES publication (title_canonical);
ALTER TABLE accessory ADD CONSTRAINT FK_A1B1251C5CBDA8E FOREIGN KEY (attribute_name) REFERENCES attribute (name_canonical);
CREATE INDEX IDX_A1B1251CCEE83EE7 ON accessory (publication_title);
CREATE INDEX IDX_A1B1251C5CBDA8E ON accessory (attribute_name);

解决此问题的正确方法是什么？我应该手动编辑表格还是使用 Doctrine 编辑表格？

根据我读到的关于 errno 150 的内容，需要为外部列建立索引，但 Doctrine 不能自动处理这个吗？

Answer 1

可以添加unique=true到 $nameCanonical 和 $titleCanonical 属性或外键引用的任何列。然后删除并运行模式更新命令以重新创建表。

在 $titleCanonical 的情况下

/**
 * @var string
 *
 * @ORM\Column(name="title_canonical", type="string", length=255, unique=true)
 */
private $titleCanonical;

但理想情况下，使用 Doctrine 时，应将外键引用到另一个表的主键以使其有效。