Doctrine ORM self ManyToOne 由于重复条目而无法插入

Question

问题

有没有一种方法可以让 Doctrine 在 ManyToOne 关系上持续使用 cascade={"persist"} 时识别现有对象，并且在尝试再次插入时不会失败，从而违反唯一键规则？

说明

我正在尝试创建一个可以引用父级的位置实体来获得这种结构：

为此，我的实体上有以下代码：

/**
 * Abstract class representing a location
 *
 * @ORM\Entity
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="type", type="string")
 * @ORM\DiscriminatorMap({"COUNTRY" = "CountryLocation", "REGION" = "RegionLocation", "DEPARTMENT" = "DepartmentLocation"})
 * @ORM\Table(name="ss_locations")
 *
 * @package Locations
 */
abstract class ALocation {
  
  /**
   * A type that determines the location type
   */
  protected ?string $type = null;
  
  /**
   * The location ID
   *
   * @ORM\Id
   * @ORM\GeneratedValue
   * @ORM\Column(type="integer", options={"unsigned"=true})
   *
   * @var int
   */
  protected int $id;
  
  /**
   * The location's slug identifier
   *
   * @ORM\Column(type="string")
   *
   * @example "Pays de la Loire" region's slug will be "pays-de-la-loire"
   *
   * @var string
   */
  protected string $slug;
  
  /**
   * The location path through its parent's slugs
   *
   * @ORM\Column(type="string", unique=true)
   *
   * @example "Loire-Atlantique" department's path would be "france/pays-de-la-loire/loire-atlantique"
   *
   * @var string
   */
  protected string $path;
  
  /**
   * The name location's
   *
   * @ORM\Column(type="string")
   *
   * @var string
   */
  protected string $name;
  
  /**
   * The parent location instance
   *
   * @ORM\ManyToOne(targetEntity="ALocation", cascade={"persist"})
   * @ORM\JoinColumn(name="parent", referencedColumnName="id")
   *
   * @var ALocation|null
   */
  protected ?ALocation $parent = null;

  // ...

}

// Example of child class 

/**
 * Class DepartmentLocation
 *
 * @ORM\Entity
 *
 * @package Locations
 */
class DepartmentLocation extends ALocation {
  const TYPE = "DEPARTMENT";
  
  /**
   * @inheritdoc
   */
  protected ?string $type = "DEPARTMENT";

  // ...
}

表创建顺利，但是当我尝试保留一个位置时，我得到了这些错误：

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'FR' for key 'PRIMARY')
Warning: Île-de-France cannot be inserted in DB : reason(An exception occurred while executing 'INSERT INTO ss_locations (iso_code, name, parent_id, type) VALUES (?, ?, ?, ?)' with params ["FR", "France", null, "COUNTRY"]:

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'FR' for key 'PRIMARY')
Warning: Paris cannot be inserted in DB : reason(An exception occurred while executing 'INSERT INTO ss_locations (iso_code, name, parent_id, type) VALUES (?, ?, ?, ?)' with params ["FR", "France", null, "COUNTRY"]:

这是所需数据库内容的示例

这是我尝试坚持的方式：

// ...

  foreach ( $locations as $location ) :
    try {
      DoctrineEntityManager::get()->persist($location);
      DoctrineEntityManager::get()->flush();
    } catch ( Throwable $e ) {}
  }

// ...

Answer 1

搜索后，我设法使用EntityManager::merge( $entity );，然后调用EntityManager::flush(); 使其工作，就像这里描述的https://stackoverflow.com/a/46689619/8027308。

// ...

foreach ( $locations as $location ) :
  // Persist the main location
  try {
    DoctrineEntityManager::get()->merge($location);
    DoctrineEntityManager::get()->flush();
  } catch ( Throwable $e ) {}
endforeach;

// ...

但是，EntityManager::merge( $entity ) 被标记为已弃用，将从 Doctrine 3+ 中删除。目前还没有官方替代方案，而且可能不会。

解决方法

1。 EntityManager::getUnitOfWork()::registerManaged()

我尝试了这里提出的替代方案https://stackoverflow.com/a/65050577/8027308，但在我的情况下使用EntityManager::getUnitOfWork()::registerManaged() 不起作用，并导致与之前SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'FR' for key 'PRIMARY') 相同的错误。 此外，这种替代方案需要一个或两个以上的依赖项才能将实体数据转换为数组。这是产生错误的代码：

use Symfony\Component\Serializer\Serializer;
use Symfony\Component\Serializer\Normalizer;

// ...  

$serializer = (new Serializer([new Normalizer\ObjectNormalizer()], []));
foreach ( $locations as $location ) :
  // Persist the main location
  try {
    DoctrineEntityManager::get()->getUnitOfWork()->registerManaged(
      $location, // The entity object
      [ $location->getIsoCode() ], // The entity identifiers
      $serializer->normalize($location, null) // Gets the entity data as array
    );
    DoctrineEntityManager::get()->flush();
  } catch ( Throwable $e ) {}
endforeach;

// ...

2。让 Doctrine 做一个预查询来检查父实体是否存在

否则，您可以在您的实体属性上禁用 cascade={"persist"} 并自己进行级联，使用 Doctrine 执行预查询以检查实体是否已存在于 DB 中：

// ...

/**
 * Recursively save all the parents into the DB
 * 
 * @param ALocation $location The location to save the parents from
 *                            
 * @return void
 */  
function persistParents( ALocation $location ) : void {
  // If we don't have any parent, no need to go further
  if ( ! $location->hasParent() )
    return;
  
  $parent = $location->getParent();
  
  // Recursion to save all parents
  if ($parent->hasParent())
    persistParents($parent);
  
  // Try to get the parent from the DB
  $parentRecord = DoctrineEntityManager::get()->getRepository( ALocation::class )->find( $parent->getIsoCode() );
  
  // If we succeed, we set the parent on the location and exit
  if ( ! is_null($parentRecord) ) {
    $location->setParent( $parentRecord );
  
    return;
  }
  
  // Otherwise, we save it into the DB 
  try {
    DoctrineEntityManager::get()->persist( $parent );
    DoctrineEntityManager::get()->flush();
  } catch (Throwable $e) {}
  
  return;
}

foreach ( $locations as $location ) :
  // Saves all the parents first
  if ($location->hasParent())
    persistParents( $location );
  
  // Then persist the main location
  try {
    DoctrineEntityManager::get()->persist($location);
    DoctrineEntityManager::get()->flush();
  } catch ( Throwable $e ) {}
endforeach;

// ...

3。使用好旧的INSERT ... ON DUPLICATE KEY UPDATE

以前的解决方法只想使用 Doctrine，但更安全和更清洁的解决方案是使用本机 SQL 查询，如下所述：https://stackoverflow.com/a/4205207/8027308

Answer 2

问题不在于您的 Doctrine 配置，而在于您如何创建对象，如果您查看这些错误消息，您会发现 Doctrine 尝试为 France 和 Paris 插入相同的数据，尝试添加 @987654323 @属性没有学说映射到

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'FR' for key 'PRIMARY')
Warning: Île-de-France cannot be inserted in DB : reason(An exception occurred while executing 'INSERT INTO ss_locations (iso_code, name, parent_id, type) VALUES (?, ?, ?, ?)' with params ["FR", "France", null, "COUNTRY"]:

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'FR' for key 'PRIMARY')
Warning: Paris cannot be inserted in DB : reason(An exception occurred while executing 'INSERT INTO ss_locations (iso_code, name, parent_id, type) VALUES (?, ?, ?, ?)' with params ["FR", "France", null, "COUNTRY"]:

更新

正如回复中所讨论的，主要问题来自于构造实体的方式，解决方案是为父实体创建唯一的对象，然后将它们附加到所有子实体（使用引用）

$france = new CountryLocation('France');
$iledefrance = new DepartmentLocation('Ile-de-france');
$iledefrance->setParent($france);
$paris = new CityLocation('Paris');
$paris->setParent($iledefrance);
....