c# - 保存时拥有的类型映射EF Core失败

Question

我想使用拥有的类型进行TableSplitting。我有以下模型:

public class Account 
{
  public GUID Id { get; set; }
  public string Email { get; set; }
  public StreetAddress Address { get; set; }
}

public class StreetAddress
{
  public string Name { get; set; }
  public string Address { get; set; }
  public string Zipcode { get; set; }
  public string City { get; set; }
  public string  Country { get; set; }
  public Location Location { get; set; }
}

public class Location
{
  public double Lat { get; set; }
  public double Lng { get; set; }
}

我定义了我的帐户映射，如下所示:

public override void Map(EntityTypeBuilder<Account> map)
{
    // Keys
    map.HasKey(x => x.Id);

    // Indexs
    map.HasIndex(x => x.Email).IsUnique();

    // Property mappings.
    map.Property(x => x.Email).HasMaxLength(255).IsRequired();

    // Owned types.
    map.OwnsOne(x => x.Address, cb => cb.OwnsOne(a => a.Location));
}

当我运行迁移时，一切正常，并且在数据库中创建了列。但是，当我尝试插入并保存地址时，如下所示:

var account1 = new Account("e@mail.com", "First", "Last")
    {
      Address = new StreetAddress()
                  {
                        Address1 = "Street 1",
                        City = "City",
                        Zipcode = "2000",
                        Country = "Denmark",
                        Location = new Location()
                        {
                            Lat = 0.0,
                            Lng = 5.5
                        }

                    }
                };
this.Context.Accounts.Add(account1);

我得到这个错误

Message "The entity of 'Account' is sharing the table 'Accounts' with 'Account.Address#StreetAddress', but there is no entity of this type with the same key value 'Id:b7662057-44c2-4f3f-2cf0-08d504db1849' that has been marked as 'Added'."

Answer 1

您必须添加构造函数并初始化拥有的实体。

public class Account 
{
  public Account (){
    Address = new StreetAddress();
  }

  public GUID Id { get; set; }
  public string Email { get; set; }
  public StreetAddress Address { get; set; }
}

public class StreetAddress
{
  public StreetAddress(){
    Location = new Location();
  }

  public string Name { get; set; }
  public string Address { get; set; }
  public string Zipcode { get; set; }
  public string City { get; set; }
  public string  Country { get; set; }
  public Location Location { get; set; }
}

public class Location
{
  public double Lat { get; set; }
  public double Lng { get; set; }
}

换句话说，不能有可选的拥有实体。
注意:如果您有一个非空的构造函数，由于 ef core limitations.，还必须添加一个空的构造函数