Question

我还没有找到这个具体问题的答案，也许是因为我对实体框架的新见解

我有两个实体：用户和设施。

Facility表需要所有者（用户），但Facility也可以拥有许多＆＃34; FacilityUsers＆＃34;分配给工厂。

public class User
{
    ....
    public virtual ICollection<Facility> Facilities { get; set; }
}

public Facility Facility
{
    public Guid OwnerId { get; set; }
    ...
    public virtual User Owner { get; set; }
    public virtual ICollection<User> FacilityUsers { get; set; }
}

这是我的模型构建器

////Many To Many: Users To Facilities
modelBuilder.Entity<User>()
    .HasMany(i => i.Facilities)
    .WithMany(u => u.FacilityUsers)
    .Map(m =>
    {
        m.MapLeftKey("UserId");
        m.MapRightKey("FacilityId");
        m.ToTable("UserFacility");
    });        

//One to Many: Facility To Owner
modelBuilder.Entity<Facility>()
    .HasRequired<User>(s => s.Owner)
    .WithMany(s => s.Facilities)
    .HasForeignKey(k => k.OwnerId);

问题是，当我有地图设施所有者时，我收到以下错误：导航属性＆＃39; FacilityUsers＆＃39;在类型＆＃39; MEH.Web.Models.Entities.Facility＆＃39;上声明已配置了多重冲突。

但是，当我排除设施到所有者映射时，它可以正常工作。

//One to Many: Facility To Owner
//modelBuilder.Entity<Facility>()
//    .HasRequired<User>(s => s.Owner)
//    .WithMany(s => s.Facilities)
//    .HasForeignKey(k => k.OwnerId);

问题是，设施表的 Owner_UserId 字段为空，但 OwnerId 已正确填写。我的OCD不让我继续前进，直到我解决了＆＃34; Owner_UserId＆＃34;问题

谢谢你， d

Answer 1

您无法将一个集合导航属性（Facilities）映射到两个关系。

为one-to-many关系添加另一个集合：

public class User
{
    ....
    public virtual ICollection<Facility> Facilities { get; set; }
    public virtual ICollection<Facility> OwnedFacilities { get; set; }
}

并映射它：

//One to Many: Facility To Owner
modelBuilder.Entity<Facility>()
    .HasRequired(s => s.Owner)
    .WithMany(s => s.OwnedFacilities) // <- another collection
    .HasForeignKey(k => k.OwnerId);

或保持User模型不变，但将one-to-many关系配置为单向（不带集合导航属性）：

//One to Many: Facility To Owner
modelBuilder.Entity<Facility>()
    .HasRequired(s => s.Owner)
    .WithMany() // <- no collection
    .HasForeignKey(k => k.OwnerId);

EF 6 Fluent API具有一对多和多对多的冲突多重性

1 个答案: