實體框架-代碼優先/ Fluent API-過濾的導航屬性

Question

我正在嘗試使用代碼優先方法和流暢的API定義以下三個類的關系，但是我已經走到了盡頭。

給定以下三個類：

public class Contract {
  public Contract {
    this.PaymentRequests = new HashSet<PaymentRequest>();
    this.Bills = new HashSet<Bill>();
  }

  public long Id { get; set; }
  public virtual ICollection<PaymentRequest> PaymentRequests { get; set; }
  public virtual ICollection<Bill> Bills { get; set; }
}

public class Bill {
  public Bill {
    this.PaymentRequests = new HashSet<PaymentRequest>();
  }

  public long Id { get; set; }
  public virtual Contract Contract { get; set; }
  public virtual ICollection<PaymentRequest> PaymentRequests { get; set }
}

public class PaymentRequest {
  public long Id { get; set; }
  public virtual Contract Contract { get; set; }
  public virtual Bill Bill { get; set; }
}

我想通過以下方式定義關系：合同維護一個尚未設置帳單的PaymentRequests清單，以及一個包含將Bills設置為當前帳單的PaymentRequests清單的帳單清單。

因此，我嘗試相應地設置映射：

public class ContractMap : EntityTypeConfiguration<Contract> {
  public ContractMap() {
    this.HasKey(x => x.Id);

    this.HasMany(x => x.PaymentRequests)
        .WithRequired(pr => pr.Contract);
    this.HasMany(x => x.Bills)
        .WithRequired(b => b.Contract);
  }
}

public class BillMap : EntityTypeConfiguration<Bill> {
  public BillMap() {
    this.HasKey(x => x.Id);

    this.HasRequired(x => x.Contract);
    this.HasMany(x => x.PaymentRequests)
        .WithRequired(x => x.Bill);
  }
}

public class PaymentRequestMap : EntityTypeConfiguration<PaymentRequest> {
  public PaymentRequestMap() {
    this.HasKey(x => x.Id);

    this.HasRequired(x => x.Contract);
    this.HasOptional(x => x.Bill);
  }
}

但這並不能真正起作用。 是否有可能定義這種關系，還是我需要創建另一個成員，例如，稱為OpenPaymentRequests，並告訴EF忽略它，然后將其填充到（例如）存儲庫中，並對帳單中的PaymentRequests執行相同的操作？ 我無法在網上找到類似內容，無法獲得解決上述問題的最佳實踐方法的有用信息。 任何輸入都非常歡迎和贊賞！

Answer 1

您正在通過自己的ContractMap和BillMap類將PaymentRequests配置為同時要求Bill和Contract 。 出於您的目的， PaymentRequest只需要一個Contract - Bill應該是可選的（就像您在PaymentRequestMap類中選擇的PaymentRequestMap ，由於前兩個配置類，實際上並不需要）

public class ContractMap : EntityTypeConfiguration<Contract> {
  public ContractMap() {
    this.HasKey(x => x.Id);

    this.HasMany(x => x.PaymentRequests)
        .WithRequired(pr => pr.Contract);
    this.HasMany(x => x.Bills)
        .WithRequired(b => b.Contract);
  }
}

public class BillMap : EntityTypeConfiguration<Bill> {
  public BillMap() {
    this.HasKey(x => x.Id);

    this.HasRequired(x => x.Contract);
    this.HasMany(x => x.PaymentRequests)
        // change this to .WithOptional( x => x.Bill )
        .WithOptional(x => x.Bill);
  }
}

public class PaymentRequestMap : EntityTypeConfiguration<PaymentRequest> {
  public PaymentRequestMap() {
    this.HasKey(x => x.Id);

    this.HasRequired(x => x.Contract);
    this.HasOptional(x => x.Bill);
  }
}