如何在Entity Framework6的数据标注中添加复合外键

Question

我正在与实体框架6的ASP.NET应用程序。我已经有数据库，我正在使用代码优先现有的数据库方法。

我是两个表，第二个表有Foriegn键和它自己的主键。我使用了列顺序，但仍然收到以下错误。我已经在网上搜索过了，尝试了不同的组合，但仍然出错。

'System.Data.Entity.ModelConfiguration.ModelValidationException' occurred in EntityFramework.dll but was not handled in user code Sys_Nav_FunctionHierarchyEntity_Sys_Nav_FunctionEntity_Source: : Multiplicity is not valid in Role  'Sys_Nav_FunctionHierarchyEntity_Sys_Nav_FunctionEntity_Source' in relationship 'Sys_Nav_FunctionHierarchyEntity_Sys_Nav_FunctionEntity'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'.

A类

 [Table("Sys_Nav_Function")]
 public class Sys_Nav_FunctionEntity
 {
    public Sys_Nav_FunctionEntity()
    { }


    [Key]
    public int Function_ID { get; set; }

    [StringLength(250)]
    [Required(ErrorMessage = "Required Title")]
    [Display(Name = "Function Title")]
    public string FunctionName { get; set; }

    [Required(ErrorMessage = "Required Hierarchy Level")]
    [Display(Name = "Hierarchy Level")]
    public int Hierarchy_Level { get; set; }


    public Sys_Nav_FunctionHierarchyEntity Sys_Nav_FunctionHierarchyEntity { get; set; }

    public ICollection<Sys_Nav_FunctionInActionEntity> Sys_Nav_FunctionInActionEntity { get; set; }

    public ICollection<Sys_Nav_FunctionInControllerEntity> Sys_Nav_FunctionInControllerEntity { get; set; }
}

B类

 [Table("Sys_Nav_FunctionHierarchy")]
public class Sys_Nav_FunctionHierarchyEntity
{
    public Sys_Nav_FunctionHierarchyEntity()
    {

    }


    [Key, Column(Order =0)]
    public int Hierarchy_ID { get; set; }

    [ForeignKey("Sys_Nav_FunctionEntity"), Column(Order =1)]
    public int Function_ID { get; set; }

    public int Parent_Function_ID { get; set; }

    public Sys_Nav_FunctionEntity Sys_Nav_FunctionEntity { get; set; }
}

​

​

Answer 1

尝尝这个

[Table("Sys_Nav_FunctionHierarchy")]
public class Sys_Nav_FunctionHierarchyEntity
{
    public Sys_Nav_FunctionHierarchyEntity()
    {

    }


    [Key, Column(Order =0)]
    public int Hierarchy_ID { get; set; }

    [ForeignKey("Function_ID"), Column(Order =1)]
    public int Function_ID { get; set; }

    public int Parent_Function_ID { get; set; }

    public Sys_Nav_FunctionEntity Sys_Nav_FunctionEntity { get; set; }
}

类B中的外键链接到表，而不是属性。

我相信上面的代码应该会给出正确的结果

Answer 2

我认为应该在导航属性上设置ForeignKey属性：

[Table("Sys_Nav_FunctionHierarchy")]
public class Sys_Nav_FunctionHierarchyEntity
{
    //...
    public int Function_ID { get; set; }

    [ForeignKey("Function_ID")]
    public Sys_Nav_FunctionEntity Sys_Nav_FunctionEntity { get; set; }
}

如果Parent_Function_ID也是同一个表的外键，则可以采用相同的方法。

另外，在第一个类中：

public Sys_Nav_FunctionHierarchyEntity Sys_Nav_FunctionHierarchyEntity { get; set; }

应该是一个集合(如果我正确理解了这个问题)

Answer 3

我已经删除了组合键，我尝试了不同的组合，但没有成功，但它的工作使用相同的键作为外键，也改变了在数据库中。

[Table("Sys_Nav_FunctionHierarchy")]
public class Sys_Nav_FunctionHierarchyEntity
{
    public Sys_Nav_FunctionHierarchyEntity()
    {

    }

    [Key, ForeignKey("Sys_Nav_FunctionEntity")]
    [Required]
    public int Function_ID { get; set; }

    public int Parent_Function_ID { get; set; }

    public Sys_Nav_FunctionEntity Sys_Nav_FunctionEntity { get; set; }
}