映射DTO回用AutoMapper

Question

型號我有一個支架型號：

public partial class Fixture 
{ 
    public int FixtureId { get; set; } 
    public string Season { get; set; } 
    public byte Week { get; set; } 

    //foreign key 
    public int AwayTeamId { get; set; } 
    //navigation properties 
    public virtual Team AwayTeam { get; set; } 

    //foreign key 
    public int HomeTeamId { get; set; } 
    //navigation properties 
    public virtual Team HomeTeam { get; set; } 

    public byte? AwayTeamScore { get; set; } 
    public byte? HomeTeamScore { get; set; } 
} 

以及器具DTO：

public class FixtureDTO 
{ 
    public int Id { get; set; } 
    public string Season { get; set; } 
    public byte Week { get; set; } 
    public string AwayTeamName { get; set; } 
    public string HomeTeamName { get; set; } 
    public byte? AwayTeamScore { get; set; } 
    public byte? HomeTeamScore { get; set; } 
} 

我使用AutoMapper的映射，這是使用它我第一次嘗試。這裏是我的映射：

CreateMap<Fixture, FixtureDTO>() 
      .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.FixtureId)) 
      .ForMember(dest => dest.AwayTeamName, opt => opt.MapFrom(src => src.AwayTeam.TeamName)) 
      .ForMember(dest => dest.HomeTeamName, opt => opt.MapFrom(src => src.HomeTeam.TeamName)); 
     CreateMap<FixtureDTO, Fixture>(); 

它可以在拍攝夾具並將其映射到FixtureDTO，我用它來顯示數據正常。但是，當我想更新數據並通過FixtureDTO回映射回夾具我得到一個錯誤。

public HttpResponseMessage PutFixture(int id, FixtureDTO fixture) 
    { 
     if (ModelState.IsValid && id == fixture.Id) 
     { 
      //do mapping manually here? 

      var updated = _repository.UpdateFixture(Mapper.Map<Fixture>(fixture)); 
      return Request.CreateResponse(updated ? HttpStatusCode.OK : HttpStatusCode.NotFound); 
     } 
     return Request.CreateResponse(HttpStatusCode.BadRequest); 
    } 

這是錯誤我得到：

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries. 

任何人可以在這方面幫助？

編輯：當實體您嘗試這通常發生：反向映射：

CreateMap<Fixture, FixtureDTO>() 
      .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.FixtureId)) 
      .ForMember(dest => dest.AwayTeamName, opt => opt.MapFrom(src => src.AwayTeam.TeamName)) 
      .ForMember(dest => dest.HomeTeamName, opt => opt.MapFrom(src => src.HomeTeam.TeamName)); 
     CreateMap<FixtureDTO, Fixture>() 
      .ForMember(dest => dest.FixtureId, opt => opt.MapFrom(src => src.Id)) 
      .ForMember(dest => dest.AwayTeam.TeamName, opt => opt.MapFrom(src => src.AwayTeamName)) 
      .ForMember(dest => dest.HomeTeam.TeamName, opt => opt.MapFrom(src => src.HomeTeamName)); 

Answer 1

@ lazyberezovsky的擴展回答：

這是您可能需要的反向映射（未經測試）的示例：

CreateMap<FixtureDTO, Fixture>() 
     .ForMember(dest => dest.FixtureId, 
        opt => opt.MapFrom(src => src.Id)) 
     .ForMember(dest => dest.AwayTeam, 
        opt => opt.MapFrom(src => new Team 
               { 
                TeamName = src.AwayTeamName 
               })) 
     .ForMember(dest => dest.HomeTeam, 
        opt => opt.MapFrom(src => new Team 
               { 
                TeamName = src.HomeTeamName 
               })); 

我已經使用在過去和它工作得很好這種格式，但或者你也可以創建團隊特定的映射。例如：

CreateMap<string, Team>().... 

此外，我認爲你這樣做，但斷言你的配置是有效的。例如：

[Test] 
public void AutoMapper_Configuration_IsValid() 
{ 
    Mapper.Initialize(m => m.AddProfile<MyProfile>()); 
    Mapper.AssertConfigurationIsValid(); 
} 

Answer 2

普遍認爲異常是由EF拋出，當它檢測到以下之一：

Opimistic併發衝突編輯被修改，否則在你加載，編輯和保存的時候。 （請參閱：Entity Framework: "Store update, insert, or delete statement affected an unexpected number of rows (0)."）

錯誤設置ID：沒有爲Pks或FK設置ID。我也看到類似這樣的，當我錯誤地設置一個實體的FK的值和相關的對象用不同的ID設置到對象的異常。

這很可能異常被拋出的，因爲在你的倉庫一些代碼。如果您將代碼發佈到存儲庫中，我們可能會更好地瞭解導致異常的原因。

Answer 3

首先，你需要從DTO創建反向映射到實體（提供自定義成員映射，如果需要的話）：

Mapper.CreateMap<FixtureDTO, Fixture>(); 

其次 - 檢索，地圖，和更新現有的實體

if (ModelState.IsValid && id == fixture.Id) 
{ 
    Fixture entity = _repository.FindById(fixture.Id); 
    Mapper.Map(fixture, entity); // Use this mapping method! 
    var updated = _repository.UpdateFixture(entity); 
    // etc 
}