Question

我正在尝试在实体中映射相同类型的2个属性并收到此错误：

An exception was thrown while executing a resolve operation. See the InnerException for details. ---> Introducing FOREIGN KEY constraint 'FK_dbo.Client_dbo.Messagebox_OutboxId' on table 'Client' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.

无法创建约束。查看以前的错误。（详见内部异常。）

据我所知，这个错误与我有两个相同类型的道具有关。

如何使用代码优先使用+ EF fluent API？

场景：每个Client都有Inbox和Outbox，其中Messagebox

 public class BaseEntity
{
    public int Id { get; set; }
}

public class Client : BaseEntity
{
    /// <summary>
    /// Gets or sets Client Alias
    /// </summary>
    public string Alias { get; set; }

    /// <summary>
    /// Gets or sets value indicating if the client was deleted
    /// </summary>
    public bool Deleted { get; set; }

    /// <summary>
    /// Gets or sets client's inbox
    /// </summary>
    public virtual Messagebox Inbox { get; set; }

    /// <summary>
    /// Gets or sets inbox Id
    /// </summary>
    public int InboxId { get; set; }

    /// <summary>
    /// Gets or sets client's outbox
    /// </summary>
    public virtual Messagebox Outbox { get; set; }

    /// <summary>
    /// Gets or sets outbox Id
    /// </summary>
    public int OutboxId { get; set; }
}

public class Messagebox : BaseEntity
{
    public int ClientId { get; set; }

    /// <summary>
    /// Gets or sets the messagebox client
    /// </summary>
    public virtual Client Client { get; set; }
}

Answer 1

此问题与使用两个具有相同名称的专业人员无关。它与sql数据库有关，不愿意创建表之间的循环约束。

您可以使用下面的流畅API克服此问题（请根据您的需求进行调整）

modelBuilder.Entity<Leaves>().HasRequired(l => l.Applicant)
                            .WithMany(bp => bp.LeavesToApply)
                            .HasForeignKey(l => l.ApplicantId)
                            .WillCascadeOnDelete(false);
modelBuilder.Entity<Leaves>().HasOptional(t => t.Approver)
                             .WithMany(bp => bp.LeavesToApprove)
                             .HasForeignKey(u => u.ApproverId)
                             .WillCascadeOnDelete(false);

事情是你必须转向Cascade。并手动删除或删除循环。

实体框架代码优先 - 相同类型的2个实体

1 个答案: