EF Core ModelBuilder不是有效的表达流利的api

Question

当我尝试在程序包管理器中执行命令add-migration时，出现以下错误。

  

表达式'a => a.Customer'不是有效的属性表达式。该表达式应表示一个简单的属性访问：“ t => t.MyProperty”。

这是类图的图像

以及我在其中定义表之间关系的BankContext.cs类的代码

namespace Bank.Datalayer
{
    public class BankContext : DbContext
    {
        public DbSet<Account> Accounts { get; set; }
        public DbSet<City> Cities { get; set; }
        public DbSet<Customer> Customers { get; set; }
        // TODO: Vul deze klasse aan
        public BankContext() { }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("Server = (localdb)\\mssqllocaldb; Database =  BankDB; Trusted_Connection = true");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        //Primary key
        modelBuilder.Entity<City>()
            .HasKey(c => c.ZipCode);
        modelBuilder.Entity<Account>()
            .HasKey(a => a.Id);
        modelBuilder.Entity<Customer>()
            .HasKey(c => c.CustomerId);

        //Foreign Keys
        modelBuilder.Entity<Account>()
            .HasOne(a => a.Customer)
            .WithMany(c => c.Accounts)
            .HasForeignKey(c => c.CustomerId);


        modelBuilder.Entity<City>()
            .HasMany(c => c.Customers)
            .WithOne(customer => customer.City)
            .HasForeignKey(c => c.Name);

        base.OnModelCreating(modelBuilder);
    }

    public void CreateOrUpdateDatabase()
    {
        Database.Migrate();
    }
}

最后但并非最不重要的是，我的Account类中发生所有麻烦的代码

namespace Bank.DomainClasses
{
    public class Account
    {
        // TODO: vul deze klasse aan
        public int Id { get; set; }
        public int AccountNumber { get; set; }
        public decimal Balance { get; set; }
        public AccountType AccountType { get; set; }
        public int CustomerId { get; set; }

        public Customer Customer;
    }
}

我已经尝试过将客户资产设置为“虚拟”，但无法使用。

Answer 1

您需要将public Customer Customer;更改为public Customer Customer { get; set; }。当前Customer是 field 而不是属性。