php – 在Doctrine 2中使用类表继承时：如何编写将从子类返回结

<?php

use DoctrineORMQueryResultSetMapping;

// Equivalent DQL query: "select u from User u where u.name=?1"
// User is a mapped base class for other classes. User owns no associations.
$rsm = new ResultSetMapping;
$rsm->addEntityResult('User','u');
$rsm->addFieldResult('u','id','id');
$rsm->addFieldResult('u','name','name');
$rsm->addMetaResult('u','discr','discr'); // discriminator column
$rsm->setDiscriminatorColumn('u','discr');

$query = $this->_em->createNativeQuery('SELECT id,name,discr FROM users WHERE name = ?',$rsm);
$query->setParameter(1,'romanb');

$users = $query->getResult();

从示例：

Note that in the case of Class Table Inheritance,an example as above
would result in partial objects if any objects in the result are
actually a subtype of User. When using DQL,Doctrine automatically
includes the necessary joins for this mapping strategy but with native
SQL it is your responsibility.

上述查询的问题是,如果您希望从子类返回上述示例中不返回它们的字段,它将从父类User返回字段.我们如何做到这一点？

在我继续前进之前,我花时间创建了一些示例类(一个是父项,另一个是子项),这应该适用于上面的示例查询.让我为你提供：

/**
 * @ORMTable(name="users",* @ORMEntity
 * @ORMInheritanceType("JOINED")
 * @ORMDiscriminatorColumn(name="discr",type="string")
 * @ORMDiscriminatorMap({
 *  "regular_user" = "RegularUser",*  "administrator" = "Administrator",* })
 */
class User
{
    /**
     * @ORMId
     * @ORMGeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORMColumn(name="name",type="string")
     */
    protected $name;
}

和：

/**
 * @ORMTable(name="regular_users",* @ORMEntity
 */
class RegularUser extends User
{
    /**
     * @ORMColumn(name="phone_number",type="string")
     */
    protected $phoneNumber;
}

所以我们有一个父类User,它有两个子类RegularUser和Administrator(注意：我只提供了一个子类RegularUser,但我确实提供了子类Administrator的鉴别器映射).

考虑一下：我们不想使用名为’romanb’的用户查询数据库(如上图所示),而是使用像Solr这样的全文搜索引擎来索引数据库.我们查询Solr for romanb,它返回一个用户id的数组,用户名为romanb,按相关性排序.使用这些有序ID,我们想查询数据库并返回常规用户列表,完全水合(即包括他们的电话号码),并按照与Solr返回的id相同的顺序排序.我们应该怎么做？

Doctrine不支持自定义排序,因为它不受所有SQL引擎的支持. MySQL支持它,它恰好是我们正在使用的数据库.

请考虑以下Native SQL Query：

$rsm = new ResultSetMapping;
$rsm->addEntityResult('User','discr');
$rsm->setDiscriminatorColumn('u','discr');
$rsm->addFieldResult('u','phone_number','phoneNumber'); // How do we map this result?

// Returned by Solr
$userIds = array(22,3,88,109,12);

$sql = <<<SQL
  SELECT u.id,u.name,u.discr,r.phone_number
  FROM users u
  INNER JOIN regular_users r ON users.id = regular_users.id
  WHERE u.id IN (?)
  ORDER BY FIELD(u.id,?); # Custom SQL logic that will return an ordered set
SQL;

$query = $this->_em->createNativeQuery($sql,$userIds);
$query->setParameter(2,$userIds);

$users = $query->getResult();

虽然SQL很好,但上面的查询将失败并出现错误.如果我们注释掉$rsm-> addFieldResult(‘u’,’phone_number’,’phoneNumber’)它会工作,并且会在结果中返回一个RegularUser对象(因为所有id都属于普通用户,我们定义了discriminator列在结果集映射中)但这些RegularUser对象都不包含电话号码.

反正有没有做一个返回完全水合的RegularUser对象的查询？

谢谢阅读.