具有来自两个不同表 mvc 的两个外键的复合主键

Question

我是 ASP.NET MVC 的新手，我试图为此找到解决方案，但找不到类似的示例，我读到这是因为我的关系在它时为空必须 *。我希望我的 ProposalFB table 具有来自不同 tables（讲师和学生）的讲师电子邮件（lecEmail）和学生电子邮件（studEmail）的复合主键，起初，我想如果讲师和学生中有数据，我可以修复它 table 不幸的是，这不起作用。每当我尝试搭建脚手架时，我都会得到

我的模型是这样的： Student.cs

public class Student
{
    [Key]
    public string studEmail { get; set; }
    public string projectType { get; set; }
    public string projectTitle { get; set; }
    [DisplayFormat(DataFormatString = "{0:dd/MM/yyyy}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> year { get; set; }
    public virtual ProposalFB ProposalFB { get; set; }
}

Lecturer.cs

public class Lecturer
{
    [Key]
    public string lecEmail { get; set; }
    public virtual ProposalFB ProposalFB { get; set; }
}

ProposalFB.cs

public class ProposalFB
{
    [Key, ForeignKey("Student"), Column(Order = 0)]
    public string studEmail { get; set; }
    [Key, ForeignKey("Lecturer"), Column(Order = 1)]
    public string lecEmail { get; set; }
    public string feedback1 { get; set; }
    public string feedback2 { get; set; }
    public string feedback3 { get; set; }
    public string feedback4 { get; set; }
    public string feedback5 { get; set; }
    public float proposalMark { get; set; }
    public Nullable<System.DateTime> createdOn { get; set; }
    public Nullable<System.DateTime> modified { get; set; }
    public bool status { get; set; }
    public virtual Student Student { get; set; }
    public virtual Lecturer Lecturer { get; set; }
}

非常感谢有关如何更正此问题的一些指导

Answer 1

您的 ProposalFB 实体表示 Student 和 Lecturer 之间的 many-to-many 关系。因此 Student 和 Lecturer 不能有单个项目 ProposalFB 属性，它应该是 ProposalFB:

的集合

public class Student
{
    // ...
    public virtual ICollection<ProposalFB> ProposalFB { get; set; }
}

public class Lecturer
{
    // ...
    public virtual ICollection<ProposalFB> ProposalFB { get; set; }
}

具有来自两个不同表 mvc 的两个外键的复合主键

Composite primary key with two foreign keys from two different tables mvc

model-view-controller

asp.net-mvc

orm

entity-framework

composite-primary-key