Asp.net 实体框架：如何解决外键约束可能导致循环或多个级联路径

关于这个问题有很多问题，但我无法解决我的问题.

我有一个Office表，它与Doctor和Secretary表有一个多关系.最后两个表都来自Employee表，Employee表与sqlmembershipprovider创建的预定义Users表具有共享主键关系.Users表和Roles表之间似乎有很多关系，我没有参与其中.

我的问题是在我的Employee表和Users表之间创建一个(0，1)-(1)关系，我在它们之间创建了一个共享主键关系，然后出现了错误.(有更好的解决方案吗？)

here is the error:

引入外键约束

here are my codes and membership codes after reverse engineering:

public class Office
{
    public Office()
    {
        this.Doctors = new HashSet<Doctor>();
        this.Secretaries = new HashSet<Secretary>();
    }

    [Key]
    public System.Guid OfficeId { get; set; }
    public virtual ICollection<Doctor> Doctors { get; set; }
    public virtual ICollection<Secretary> Secretaries { get; set; }
}

public class Employee
{
    [Key, ForeignKey("User")]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public System.Guid Id { get; set; }
    public string Name { get; set; }

    [ForeignKey("Office")]
    public System.Guid OfficeId { get; set; }

    // shared primary key 
    public virtual aspnet_Users User { get; set; }

    public virtual Office Office { get; set; }
}

public class Doctor :Employee
{
    public Doctor()
    {
        this.Expertises = new HashSet<Expertise>();
    }
    //the rest..    
    public virtual ICollection<Expertise> Expertises { get; set; }
}

public class Secretary : Employee
{
    // blah blah
}

public class aspnet_Users
{
    public aspnet_Users()
    {
        this.aspnet_Roles = new List<aspnet_Roles>();
    }

    public System.Guid ApplicationId { get; set; }
    public System.Guid UserId { get; set; }
    //the rest..
    public virtual aspnet_Applications aspnet_Applications { get; set; }
    public virtual ICollection<aspnet_Roles> aspnet_Roles { get; set; }
}

public class aspnet_Roles
{
    public aspnet_Roles()
    {
        this.aspnet_Users = new List<aspnet_Users>();
    }

    public System.Guid ApplicationId { get; set; }
    public System.Guid RoleId { get; set; }
    //the rest..
    public virtual aspnet_Applications aspnet_Applications { get; set; }
    public virtual ICollection<aspnet_Users> aspnet_Users { get; set; }
}

EDIT:，而且关系更深入，Users表和Applications表之间存在多个一的关系，Roles表和Applications表之间也存在多个一的关系.