如何访问我的 Array (Symfony 4) 中的 ArrayCollection 数据？

Question

fields table:

productgroup table:

在我的控制器中，我像这样加载我的fields_array：

$fields_array = $this->getDoctrine()->getRepository(class::fields)->findAll();

如果字段和产品组未连接，我的fields_array 看起来像这样：

array:2 [▼
  0 => Fields {#7460 ▼
    -id: 3
    -name: "cat"
    -unique_id: "5a38c820ed"
    -productgroup: PersistentCollection {#7464 ▼
      -snapshot: []
      -owner: Fields {#7460}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7465 ▼
        -elements: []
      }
      #initialized: false
    }
    -type: Type {#7541 ▶}
  }
  1 => Fields {#7542 ▼
    -id: 4
    -name: "horse"
    -unique_id: "bd7762b0e6"
    -productgroup: PersistentCollection {#7543 ▼
      -snapshot: []
      -owner: Fields {#7542}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7544 ▼ 
        -elements: []
      }
      #initialized: false
    }
    -type: Type {#7545 ▶}
  }
]

如您所见，ArrayCollecton 不包含任何元素。

所以现在我将cat 与产品组Animals 连接起来。所以我的表fields_productgroup 看起来像这样：

现在如您所见，我的cat 中的ArrayCollection 包含Animals 元素：

array:2 [▼
  0 => Fields {#7460 ▼
    -id: 3
    -name: "cat"
    -unique_id: "5a38c820ed"
    -productgroup: PersistentCollection {#7464 ▼
      -snapshot: array:1 [ …1]
      -owner: Fields {#7460}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7465 ▼
        -elements: array:1 [▼
          0 => Productgroup {#7146 ▼
            -id: 6
            -name: "Animals"
            -unique_id: "9e4ef1c46f"
            -fields: PersistentCollection {#7357 ▶}
          }
        ]
      }
      #initialized: true
    }
    -type: Type {#7541 ▶}
  }
  1 => Fields {#7542 ▼
    -id: 4
    -name: "horse"
    -unique_id: "bd7762b0e6"
    -productgroup: PersistentCollection {#7543 ▼
      -snapshot: []
      -owner: Fields {#7542}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7544 ▼
        -elements: []
      }
      #initialized: false
    }
    -type: Type {#7545 ▶}
  }
]

现在我将horse 也连接到产品组Animals。所以我的表fields_productgroup 看起来像这样：

我的fields_array 用于horse 显示，ArrayCollection 中有一个元素，但它不包含Animals 的信息。它只是一个空数组......但我实际上需要连接到哪个productgroup horse 的信息

array:2 [▼
  0 => Fields {#7460 ▼
    -id: 3
    -name: "cat"
    -unique_id: "5a38c820ed"
    -productgroup: PersistentCollection {#7464 ▼
      -snapshot: array:1 [ …1]
      -owner: Fields {#7460}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7465 ▼
        -elements: array:1 [▼
          0 => Productgroup {#7146 ▼
            -id: 6
            -name: "Animals"
            -unique_id: "9e4ef1c46f"
            -fields: PersistentCollection {#7357 ▶}
          }
        ]
      }
      #initialized: true
    }
    -type: Type {#7541 ▶}
  }
  1 => Fields {#7542 ▼
    -id: 4
    -name: "horse"
    -unique_id: "bd7762b0e6"
    -productgroup: PersistentCollection {#7543 ▼
      -snapshot: array:1 [ …1]
      -owner: Fields {#7542}
      -association: array:20 [ …20]
      -em: EntityManager {#2815 …11}
      -backRefFieldName: "fields"
      -typeClass: ClassMetadata {#6494 …}
      -isDirty: false
      #collection: ArrayCollection {#7544 ▼
        -elements: array:1 [▼
          0 => Productgroup {#7146}
        ]
      }
      #initialized: true
    }
    -type: Type {#7545 ▶}
  }
]

我的字段实体：

  /**
  * @ORM\ManyToMany(targetEntity="Productgroup", inversedBy="fields")
  * @ORM\JoinColumn(name="productgroup", referencedColumnName="id")
  */
  private $productgroup;


public function getProductgroup()
  {
    return $this->productgroup;
  }

  public function setProductgroup($productgroup): self
  {
    $this->productgroup = $productgroup;

    return $this;
  }

  public function __construct()
  {
    $this->productgroup = new ArrayCollection();
  }

Answer 1

首先，我认为您将 PHP 对象与 PHP 数组混淆了。但是从您的屏幕截图来看，您似乎拥有您想要的东西，“马”对象的productgroup 关联已满载。

这可以在您的转储中观察到：

正如我们所见，猫和马对象的相关 Productgroup 对象的 uid 都是 #7146，正如预期的那样，因为它们与同一个产品组相关。

我认为您只是被马的 Productgroup 在您的转储中不可扩展的事实误导了。