使用EF Core MVC播种表数据时出错

Question

我是MVC和EF Core的新手，并且一直在尝试播种一些数据。除了一张桌子外，我所有桌子的种子都正确播种，我头撞墙撞腻了。我什至没有运气就重新创建了整个应用程序。我确定我缺少明显的东西。

我的模型

public class AgreementType
    {
        public int AgreementTypeID { get; set; }

        [Required]
        [StringLength(100)]
        public string Description { get; set; }

        [DisplayName("Creation Date")]
        public DateTime CreationDate { get; set; }

        [StringLength(100)]
        [DisplayName("Created By")]
        public string CreatedBy { get; set; }

        public Agreement Agreement { get; set; }
    }

public class ContactType
    {
        public int ContactTypeID { get; set; }

        [Required]
        [StringLength(100)]
        public string Description { get; set; }

        [DisplayName("Creation Date")]
        public DateTime CreationDate { get; set; }

        [StringLength(100)]
        [DisplayName("Created By")]
        public string CreatedBy { get; set; }

        public Contact Contact { get; set; }
    }

public class Branch
    {
        public int BranchID { get; set; }
        public string Name { get; set; }

        [DisplayName("Creation Date")]
        public DateTime CreationDate { get; set; }

        [StringLength(100)]
        [DisplayName("Created By")]
        public string CreatedBy { get; set; }

        public int IntermediaryID { get; set; }
        public Intermediary Intermediary { get; set; }

        public int RegionID { get; set; }
        public virtual Region Region { get; set; }
    }

我的上下文课程

public class BizDevHubContext : DbContext
    {
        public BizDevHubContext(DbContextOptions<BizDevHubContext> options) : base(options)
        {
        }

        public DbSet<AgreementType> AgreementType { get; set; }
        public DbSet<Branch> Branch { get; set; }
        public DbSet<ContactType> ContactTypes { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<AgreementType>().ToTable("AgreementType");
            modelBuilder.Entity<Branch>().ToTable("Branch");
            modelBuilder.Entity<ContactType>().ToTable("ContactType");

            // One to One            
            modelBuilder.Entity<Agreement>()
                .HasOne(b => b.AgreementType)
                .WithOne(i => i.Agreement)
                .HasForeignKey<Agreement>(b => b.AgreementTypeID);

            modelBuilder.Entity<Contact>()
                .HasOne(b => b.ContactType)
                .WithOne(i => i.Contact)
                .HasForeignKey<Contact>(b => b.ContactTypeID);

            //One to Many
            modelBuilder.Entity<Region>()
                .HasMany(c => c.Branch)
                .WithOne(e => e.Region)
                .HasForeignKey((p => p.BranchID));

            // Set default dates 
            modelBuilder.Entity<AgreementType>()
            .Property(b => b.CreationDate)
            .HasDefaultValueSql("getdate()");

            modelBuilder.Entity<Branch>()
            .Property(b => b.CreationDate)
            .HasDefaultValueSql("getdate()");

            modelBuilder.Entity<ContactType>()
            .Property(b => b.CreationDate)
            .HasDefaultValueSql("getdate()");
        }
    }

我的初始化器类

    if (context.Branch.Any())
                {
                    return;
                }

                var branches = new Branch[]
                {
                 new Branch{Name="Bloemfontein",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Cape Town",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Durban",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Nelspruit",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Johannesburg",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Port Shepstone",CreationDate=DateTime.Now,CreatedBy="System"},
                 new Branch{Name="Pretoria",CreationDate=DateTime.Now,CreatedBy="System"}
                };
                foreach (Branch b in branches)
                {
                    context.Branch.Add(b);

                }
                context.SaveChanges();

除“分支”表外，其他所有表都是种子。

请帮助！