参与这种关系的实体。找到0相关。预计1

Question

我正在为一所学校的项目工作，我遇到了一对一关系的问题。根据州的模式，它是关于具有某种状态（新的，被接受的等）的提议。双方都需要这种关系。这是我的代码：

用于提案的映射类：

    namespace Projecten2Groep23.Models.DAL.Mapper
{
    public class ProposalMap : EntityTypeConfiguration<Proposal>
    {


        public ProposalMap()
        {
            ToTable("Proposals");



            HasKey(p => p.ProposalId);
            Property(p => p.ProposalId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            Property(p => p.Title);
            Property(p => p.KeyWords);
            Property(p => p.Goal);
            Property(p => p.Plan);
            Property(p => p.Problems);
            Property(p => p.ResearchArea1);
            Property(p => p.ResearchArea2).IsOptional();


            HasRequired(p => p.ProposalState).WithRequiredPrincipal().Map(b=> b.MapKey("ProposalStateMapId")).WillCascadeOnDelete(true);
            //NotMapped weghalen in proposal.cs als je proposalstate wil mappen
            HasOptional(p => p.Feedback).WithRequired().Map(b => b.MapKey("FeedbackMapId")).WillCascadeOnDelete(true);

            HasOptional(p => p.CoPromotor).WithRequired().Map(b => b.MapKey("ProposalMapId")).WillCascadeOnDelete(false);

        }

    }
}

用于提案状态的映射类

 namespace Projecten2Groep23.Models.DAL.Mapper
{
    public class ProposalStateMap : EntityTypeConfiguration<ProposalState>
    {

        public ProposalStateMap()
        {
            ToTable("ProposalState");

            HasKey(p => p.ProposalStateId);
            Property(p => p.ProposalStateId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            HasRequired(p => p.Proposal).WithRequiredDependent().Map(b => b.MapKey("ProposalMapId")).WillCascadeOnDelete(true);



        }

    }
}

现在，在调用context.SaveChanges时，我不断收到标题中声明的异常。我几乎尝试了这种关系的所有配置，但它仍然没有被映射。

我已经在stackoverflow上搜索了十几篇帖子，但没有用。

编辑：有人要求保存操作

namespace Projecten2Groep23.Models.DAL
{
    public class BachProefRegistrationInitializer : DropCreateDatabaseAlways<BachProefRegistratieContext>
    {
        protected override void Seed(BachProefRegistratieContext context)
        {
            try
            {
                Student student = new Student("student", "student@student.be", true, "student");
                Proposal proposal = new Proposal("lol", "keywords", "plan", "problems", "research", null, "title", new Copromotor("copromotor", "copromotor@copromotor.be", "organisatie copromotor"), 0, "referencelist", DateTime.Now);
                proposal.ProposalState = new AdviceBPCState(proposal);
                proposal.Feedback = new Feedback();
                student.AddProposal(proposal);
                BPCoordinator bpc = new BPCoordinator("bpc", "bpc@bpc.be", true, "bpc");
                ICollection<Student> students = new List<Student>();
                students.Add(student);
                Promotor promotor = new Promotor("promotor", "promotor@promotor.be", false, "promotor", students);
                Student student2 = new Student("pieter", "p2groep23@gmail.com", false, "pieter");
                List<User> users =  (new User[] {student, bpc, promotor, student2}).ToList();

                context.Proposals.Add(proposal);
                users.ForEach(u => context.Users.Add(u));

                context.SaveChanges();
            }
            catch (DbEntityValidationException e)
            {
                string s = "Fout creatie database ";
                foreach (var eve in e.EntityValidationErrors)
                {
                    s += String.Format("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
                        eve.Entry.Entity.GetType().Name, eve.Entry.GetValidationResult());
                    foreach (var ve in eve.ValidationErrors)
                    {
                        s += String.Format("- Property: \"{0}\", Error: \"{1}\"", ve.PropertyName, ve.ErrorMessage);
                    }
                }
                throw new Exception(s);
            }
        }
    }