Question

我有一个成员模型，其地址为一对一样式，其中地址行只能属于一个成员。我正在试图找出如何定义这个，以便当我删除一个成员时，会员拥有的地址和地址被级联删除。

public class Member
{
    [Key]
    public int Id { get; set; }

    [Required]
    [ForeignKey("Address")]
    public int AddressId { get; set; }
    public virtual Address Address { get; set; }
}

我也有地址

public class Address : IEntity
{
    [Key]
    public int Id { get; set; }

    ....
}

我已尝试以下方法获取级联删除地址

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder
        .Entity<Member>()
        .HasRequired(m => m.Address)
        .WithRequiredDependent()
        .WillCascadeOnDelete(true);
}

和

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder
        .Entity<Member>()
        .HasRequired(m => m.Address)
        .WithRequiredPrinciple()
        .WillCascadeOnDelete(true);
}

有人可以帮助我走上正轨吗？迁移失败的行如下。

System.Data.Entity.ModelConfiguration.ModelValidationException: One 
or more validation errors were detected during model generation:

System.Data.Entity.Edm.EdmAssociationEnd: : Multiplicity is not valid 
in Role 'Member_Address_Source' in relationship 'Member_Address'. Because the
Dependent Role properties are not the key properties, the upper bound of the 
multiplicity of the Dependent Role must be '*'.

从docs找到这个 - 一对一只有一个导航属性

 modelBuilder.Entity<OfficeAssignment>()
    .HasKey(t => t.InstructorID);

 modelBuilder.Entity<Instructor>()
     .HasRequired(t => t.OfficeAssignment)
     .WithRequiredPrincipal();

如果我有机会，我会发布它是否有效

Answer 1

你的逻辑颠倒了。你现在写的是每个成员都有一个地址，这导致一个地址可以存在于几个成员的事实，这意味着在层次结构表中，地址在成员之上。删除子项不会导致删除父项。

尝试删除地址，如果你想测试我刚写的内容，你的会员就会消失。

为了你的逻辑工作，你需要写：

public class Member
{
    [Key]
    public int Id { get; set; }
...
}

public class Address : IEntity
{
    [Key]
    public int Id { get; set; }

    public int MemberId {get;set;}
    public virtual Member Member {get;set;}
    ....
}

如果启用级联删除和删除成员，地址也将被删除。

编辑：

如果你正在寻找一对一的关系，那就是这样：

public class Member
{
[Key]
public int Id {get;set;}

...

public virtual Address Address {get;set;}
}

public class Address
{
[ForeignKey("Member")]
public int Id {get;set;}

...

public virtual Member Member {get;set;}
}

Answer 2

我尝试了一些不同的东西，但这是EF创建一对一映射的方式，只在关系的一侧有导航..

public class Member
{
    [Key]
    public int Id { get; set; }

    public virtual Address Address { get; set; }
}

public class Address
{
    [Key]
    public int MemberId {get;set;}
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder
        .Entity<Address>()
        .HasKey(t => t.MemberID);

    modelBuilder
        .Entity<Member>()
        .HasRequired(t => t.Address)
        .WithRequiredPrincipal();
}

执行此操作可使级联删除正常工作，以便在删除成员时删除地址。

EF Code First模型定义，用于一对一映射与级联删除

2 个答案: