如何多次在对象框的框中添加相同的对象？

Question

我有如下所示的 ToMany 关系，

@Entity()
class Pdf {
  @Id()
  int id;
  Uint8List pdfData;
  final String customerName;
  @Property(type: PropertyType.date)
  final DateTime dateTime;
  @Backlink()
  var products = ToMany<Product>();
  double totalAmount;
  PaymentStatus paymentStatus;

  Pdf({
    this.id = 0,
    required this.pdfData,
    required this.dateTime,
    required this.customerName,
    required this.totalAmount,
    this.paymentStatus = PaymentStatus.unPaid,
  });

  int get status => paymentStatus.index;

  set status(int value) {
    paymentStatus = PaymentStatus.values[value];
  }
}

@Entity()
class Product {
  @Id()
  int id;
  String name;
  String category;
  int categoryId;
  WeightType weightType;
  double? price;
  double weight;
  bool isRefunded;
  final pdf = ToOne<Pdf>();

  Product({
    this.id = 0,
    required this.name,
    required this.category,
    required this.categoryId,
    this.weightType = WeightType.kg,
    this.price,
    this.weight = 0,
    this.isRefunded = false,
  });
  Product copy() => Product(
        name: name,
        category: category,
        id: id,
        price: price,
        weight: weight,
        weightType: weightType,
        categoryId: categoryId,
        isRefunded: isRefunded,
      );
  }
@override
  int get hashCode => hashValues(
        name.hashCode,
        price.hashCode,
        id.hashCode,
        category.hashCode,
        categoryId.hashCode,
        weightType.hashCode,
        weight.hashCode,
        isRefunded.hashCode,
      );

  @override
  bool operator ==(Object other) =>
      other is Product &&
      other.name == name &&
      price == other.price &&
      category == other.category &&
      categoryId == other.categoryId &&
      other.weight == weight &&
      other.weightType == weightType &&
      other.id == id;
}

我就是这样把它放在盒子里的，

void add(){
final billPdf = Pdf(
      pdfData: pdf,
      dateTime: DateTime.now(),
      customerName: bill.customerName,
      totalAmount: bill.totalAmount,
      paymentStatus: bill.paymentStatus,
    );
    billPdf.products.addAll(bill.products);
    DBService.pdfBox.put(billPdf,mode: obj.PutMode.put);
}

现在，当我尝试在 box 中添加相同的产品时，它会从列表 (db) 中删除以前的数据并仅添加最新的数据，因此它只是在更新产品。如果我将 PutMode 更改为 insert，它会给我例外。像这样，

object put failed

我为 kotlin 找到了这个，

据此，我什至覆盖了 hashcode 并输入了一些不同的值，但它仍然删除了以前的值，而且在我的用例中，一切都可以相同。

那么如何将相同的对象放入对象框中？

Answer 1

问题是我不需要在产品模型中添加 final pdf = ToOne<Pdf>(); 并从 Pdf 模型中删除 @Backlink()。它将数据放在不同的列表中，并且不会从以前的列表中删除。如果您放置重复的对象，它只会更新它。

虽然我仍然有一个问题它只存储默认值这意味着一些值可能是 null 但我认为这个问题与问题无关所以它很好并把上面作为答案。

如何多次在对象框的框中添加相同的对象？

how to add same object in objectbox's box multiple times?

flutter

objectbox

greenrobot-objectbox

flutter-objectbox