主义2：从自我反省的实体构建一个嵌套的数组树 [英] Doctrine 2: Building a nested array tree from a self-refrencing Entity

问题描述

我有一个实体，如下所示：

I have an Entity that looks like this:

class Privilege
{
/**
 * @Id @Column(type="bigint")
 * @GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @Column(type="string",length=255)
 */
private $name;

/**
 * @Column(type="string",length=255)
 */
private $slug;

/**
 * @OneToMany(targetEntity="Privilege", mappedBy="parent")
 */
private $children;

/**
 * @ManyToOne(targetEntity="Privilege", inversedBy="children")
 * @JoinColumn(name="p_id", referencedColumnName="id")
 */
private $parent;

如果特权实体没有父，该字段为NULL。我有一个这样的基本查询：

If a Privilege Entity does not have a parent, the field is NULL. I have a basic query like this:

    $qb = $this->em->createQueryBuilder()
        ->select('p')
        ->from('\Dashboard\Entity\Privilege', 'p')
        ->andWhere('p.parent IS NULL');

    $q = $qb->getQuery();
    $privileges = $q->getResult();

我希望从这个方法返回的数组结果看起来类似于这样：

I would like the array result I return from this method to look similar to this:

root1:
    child1:
        subchild1a
        subchild2a
   child2:
        subchild1b
        subchild2b
        subchild3b
            subsubchild1b
   child3:
        subchild1c
root2:
....
....

有没有办法HYDRATE从Doctrine 2的结果，所以它以这种方式构建数组结果？如果没有，你将如何构建这个数组？我仍在玩Doctrine 2，我发现我的 $特权中的每个元素都有一个 $ privilege-> getChildren（）返回 PersistentCollection ，显然不是实际记录。

Is there a way to HYDRATE the results from Doctrine 2 so it builds the array results this way? If not, how would you build this array? I am still playing around with Doctrine 2, and I noticed each element in my $privileges array has a $privilege->getChildren() which returns a PersistentCollection, obviously not the actual record.

如果我必须自己构建这个嵌套树（即：在Doctrine中没有内置的方式来做到这一点），我该怎么把这个 PersistentCollection 返回实际的数据，所以我可以建立一些递归方法来为我建立它？我正在查看文档，但显然是在错误的地方。

If I have to build this nested tree myself (ie: no built in way in Doctrine to do it), how do I turn this PersistentCollection returned into the actual data so I can build some sort of recursive method to build it for me? I am looking through the docs, but obviously in the wrong place.

推荐答案

结果已经在一个嵌套的树中。 PersistentCollection 可以像数组一样迭代：

The results are already in a nested tree. The PersistentCollection can be iterated as if it was an array:

foreach($parent->getChildren() as $child) {
    // $child is an instance of Privilige
}

仍然应该尝试 $ privileges = $ q-> getArrayResult（）; ，看看是否给出了你喜欢的结果。

Still you should try $privileges = $q->getArrayResult(); and see if that gives a result you would prefer.

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