c# - 如何在 Entity Framework 6 的数据注释中添加复合外键

Question

我正在使用 Entity Framework 6 开发 ASP.NET 应用程序。我已经有了数据库，并且正在使用 Code First 现有的数据库方法。

我有两个表，第二个表有外键和它自己的主键。我使用了 Column order 但仍然出现以下错误。我已经在线搜索，尝试了不同的组合，但仍然出现错误。

'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

试试这个

[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; }
}

B 类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你正确的结果