EF核心循环关系映射

Question

给出以下实体模型：

public class Workshop
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    public ICollection<QuoteRequest> QuoteRequests { get; set; }
}

public class QuoteRequest
{
    public Guid Id { get; set; }
    public Guid CustomerId { get; set; }
    public Guid WorkshopId { get; set; }
    public bool Responded { get; set; }
    public decimal? Amount { get; set; }

    public virtual Customer Customer { get; set; }
    public virtual Workshop Workshop { get; set; }
}

和以下两个视图模型：

public class WorkshopModel
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    public ICollection<QuoteRequestModel> QuoteRequests { get; set; }
}

public class QuoteRequestModel
{
    public Guid Id { get; set; }
    public Guid CustomerId { get; set; }
    public Guid WorkshopId { get; set; }
    public bool Responded { get; set; }
    public decimal? Amount { get; set; }

    public CustomerModel Customer { get; set; }
    public WorkshopModel Workshop { get; set; }
}

接下来，给出以下查询：

    public async Task<Workshop> GetWorkshopAsync(Guid id, bool includeQuotes = false)
    {
        IQueryable<Workshop> query = _context.Workshops;

        if (includeQuotes)
        {
            query = query.Include(w => w.QuoteRequests);
        }

        return await query.FirstOrDefaultAsync(w => w.Id == id);
    }

无论我做什么，在查询Workshop时，我都无法获得EF来不给我循环关系。例如，我查询一个具有14个Workshop的QuoteRequests，每个都有一个Workshop，每个都有14个QuoteRequests等，等等：：>

我确实将json序列化程序参考循环处理设置设置为忽略，但这没有给我想要的结果

services.AddControllers()
        .AddNewtonsoftJson(x => x.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore);
因此，我想在我的地图资料中删除该圆圈。我正在使用自动映射器。我已经从QuoteRequest端用映射配置文件打破了循环引用：

CreateMap<QuoteRequestModel, QuoteRequest>()
    .ForMember(dest => dest.Customer, opt => opt.MapFrom(src => src.Customer))
    .ForMember(dest => dest.Workshop, opt => opt.MapFrom(src => src.Workshop))
    .ForPath(dest => dest.Customer.QuoteRequests, opt => opt.MapFrom(src => new List<QuoteRequest>()))
    .ForPath(dest => dest.Workshop.QuoteRequests, opt => opt.MapFrom(src => new List<QuoteRequest>()));

CreateMap<QuoteRequest, QuoteRequestModel>()
    .ForMember(dest => dest.Customer, opt => opt.MapFrom(src => src.Customer))
    .ForMember(dest => dest.Workshop, opt => opt.MapFrom(src => src.Workshop))
    .ForPath(dest => dest.Customer.QuoteRequests, opt => opt.MapFrom(src => new List<QuoteRequestModel>()))
    .ForPath(dest => dest.Workshop.QuoteRequests, opt => opt.MapFrom(src => new List<QuoteRequestModel>()));
这可能是一个简单的解决方案，但是当我查询一个单独的QuoteRequest时，它现在可以正常工作。我想弄清楚的是，如何从Workshop端在映射配置文件中执行相同的操作：

CreateMap<WorkshopModel, Workshop>()
    .ForMember(dest => dest.QuoteRequests, opt => opt.MapFrom(src => src.QuoteRequests));

CreateMap<Workshop, WorkshopModel>()
    .ForMember(dest => dest.QuoteRequests, opt => opt.MapFrom(src => src.QuoteRequests));
我不能真正地以QuoteRequests的每次迭代为目标来将Workshop设置为默认值。

给出以下实体模型：public class Workshop {public Guid ID {get;组; } public string Name {get;组; } public ICollection QuoteRequests {get;组; } ...

Answer 1

这不是问题。您所看到的是EF的对象修复。因为它的对象缓存中已经包含这些实体，所以它会自动“修复”每个实体上的关系，而无需再次查询任何内容。