我正在尝试使用持久层和领域模型来实现仓储。我的主要目标是将领域逻辑与其他层分离,例如洋葱架构。
作为我的存储库,我使用Entity Framework 6.2。为了映射模型,我使用Automapper。
我不想使用实体模型作为我的领域模型。
我已经阅读了很多关于DDD中仓储概念和思想的文章,并浏览了许多示例,但没有一个给我答案如何处理更复杂的模型。
例如,在我的控制台应用程序中,我有一个AppUser
,其中包含BankAccounts
。当我向用户添加新的BankAccount
时,我会得到一行额外的未被跟踪的BankAccount
实体。这是因为在从领域模型映射到持久化模型(即实体)时,EF无法确定哪些BankAccounts被跟踪并将它们全部视为新的。
之前的版本:
+------------------------------------+
|Id |BankAccountNumber |AppUser_Id |
+------------------------------------+
|1 |Seeded Bank Account | 1 |
+------------------------------------+
之后
+------------------------------------+
|Id |BankAccountNumber |AppUser_Id |
+------------------------------------+
|1 |Seeded Bank Account | NULL |
+------------------------------------+
|2 |Added Bank Account | 1 |
+------------------------------------+
|3 |Seeded Bank Account | 1 |
+------------------------------------+
这是我的代码。
class Program
{
static void Main(string[] args)
{
CreateMappings();
var appUserRepository = new AppUserRepository();
var appUser = appUserRepository.Get(1);
var bankAccount = new BankAccountDM
{
BankAccountNumber = "Added Bank Account"
};
var service = new AppUserDomainSerivce(appUserRepository);
service.AddBankAccount(bankAccount, appUser);
Console.WriteLine("== END ==");
Console.ReadKey();
}
public static void CreateMappings()
{
// Config Automapper
Mapper.CreateMap<AppUserDM, AppUser>()
.ForMember(x => x.Id, opt => opt.MapFrom(y => y.Id))
.ForMember(x => x.Name, opt => opt.MapFrom(y => y.Name))
.ForMember(x => x.BankAccounts, opt => opt.MapFrom((y => y.BankAccounts)))
.ReverseMap();
Mapper.CreateMap<BankAccountDM, BankAccount>()
.ReverseMap();
}
public class AppUserDomainSerivce
{
private readonly AppUserRepository _appUserRepository;
public AppUserDomainSerivce(AppUserRepository appUserRepository)
{
_appUserRepository = appUserRepository;
}
public void AddBankAccount(BankAccountDM bankAccount, AppUserDM appUser)
{
appUser.BankAccounts.Add(bankAccount);
// Save changes
_appUserRepository.Save(appUser);
}
}
public class AppUserRepository
{
public AppUserDM Get(int id)
{
using (var ctx = new AppContext())
{
var userEntity = GetAppUser(id, ctx);
return Mapper.Map<AppUserDM>(userEntity);
}
}
public void Save(AppUserDM user)
{
// Save entity in storage
using (var ctx = new AppContext())
{
var userEntity = GetAppUser(user.Id, ctx);
userEntity = Mapper.Map(user, userEntity);
ctx.SaveChanges();
}
}
private AppUser GetAppUser(int id, AppContext ctx)
{
return ctx.AppUsers
.Include("BankAccounts")
.SingleOrDefault(x => x.Id == id);
}
}
}
// Entities and Domain Models
public class BankAccountDM
{
public int Id { get; set; }
public string BankAccountNumber { get; set; }
}
public class BankAccount
{
[Key]
public int Id { get; set; }
public string BankAccountNumber { get; set; }
}
public class AppUserDM
{
public int Id { get; set; }
public List<BankAccountDM> BankAccounts { get; set; }
public string Name { get; set; }
}
public class AppUser
{
[Key]
public int Id { get; set; }
public virtual ICollection<BankAccount> BankAccounts { get; set; }
public string Name { get; set; }
}
// Entity DbContext
public class AppContext : DbContext
{
public AppContext() : base("AppContext")
{
}
public DbSet<AppUser> AppUsers { get; set; }
}
public Configuration()
{
AutomaticMigrationsEnabled = true;
}
protected override void Seed(ConsoleApplication1.AppContext context)
{
context.AppUsers.Add(new AppUser()
{
// This AppUser will get ID = 1 once saved into DB
Name = "My Test User",
BankAccounts = new List<BankAccount>()
{
new BankAccount()
{
BankAccountNumber = "Seeded Bank Account"
}
}
});
}