RavenDB 转换结果

Question

我正在尝试使用 TransformResults 功能，但无法使用它。我不完全确定我理解这个功能，也许还有另一种方法可以解决这个问题。我想要的只是订单中的 ID 以及客户和企业家的电子邮件地址。我很高兴所有可以带我走向正确方向的提示。这是我的代码。

文档

public class OrderDocument

    public string Id {get; set }

    public EntrepreneurInfo EntrepreneurInfo { get; set; }

    public CustomerInfo CustomerInfo { get; set; }

    public OrderStatus CurrentOrderStatus { get; set; }
}

信息类

public class EntrepreneurInfo
{
    public string EntrepreneurDocumentId { get; set; }

    public string Number { get; set; }

    public string Name { get; set; }
}

public class CustomerInfo
{
    public string CustomerDocumentId { get; set; }

    public string Number { get; set; }

    public string Name { get; set; }
}

信息类分别只是 Customer 和 Entrepreneur 文档的子集。 Customer 和 Entrepreneur 文档继承自具有 EmailAddress 属性的基类 (AbstractOrganizationDocument)。

我的索引

public class OrdersApprovedBroadcastingData : 
    AbstractIndexCreationTask<OrderDocument, OrdersApprovedBroadcastingData.ReduceResult>
{
    public OrdersApprovedBroadcastingData()
    {
        this.Map = docs => from d in docs 
                           where d.CurrentOrderStatus == OrderStatus.Approved 
                            select new
                            {
                                Id = d.Id,
                                CustomerId = d.CustomerInfo.CustomerDocumentId,
                                EntrepreneurId = d.EntrepreneurInfo.EntrepreneurDocumentId
                            };

        this.TransformResults = (db, orders) => from o in orders
                let customer = db.Load<CustomerDocument>(o.CustomerId)
                let entrepreneur = db.Load<EntrepreneurDocument>(o.EntrepreneurId)
                select
                    new 
                        {
                            o.Id,
                            o.CustomerId,
                            CustomerEmail = customer.EmailAddress,
                            o.EntrepreneurId,
                            EntrepreneurEmail = entrepreneur.EmailAddress
                        };
    }

    public class ReduceResult
    {
        public string Id { get; set; }

        public string CustomerId { get; set; }

        public string CustomerEmail { get; set; }

        public string EntrepreneurId { get; set; }

        public string EntrepreneurEmail { get; set; }
    }
}

如果我在 Raven Studio 中查看此索引的结果，我会得到除 Id 之外的所有字段的空值。最后是我的查询。

查询

        var items =
            this.documentSession.Query<OrdersApprovedBroadcastingData.ReduceResult, OrdersApprovedBroadcastingData>()
                .Select(x => new OrdersToBroadcastListItem
                    {
                        Id = x.Id,
                        CustomerEmailAddress = x.CustomerEmail,
                        EntrepreneurEmailAddress = x.EntrepreneurEmail
                    }).ToList();

Answer 1

将您的索引更改为：

public class OrdersApprovedBroadcastingData : AbstractIndexCreationTask<OrderDocument>
{
  public OrdersApprovedBroadcastingData()
  {
    Map = docs => from d in docs
                  where d.CurrentOrderStatus == OrderStatus.Approved
                  select new
                  {
                  };

    TransformResults = (db, orders) =>
      from o in orders
      let customer = db.Load<CustomerDocument>(o.CustomerInfo.CustomerDocumentId)
      let entrepreneur = db.Load<EntrepreneurDocument>(o.EntrepreneurInfo.EntrepreneurDocumentId)
      select new
        {
          o.Id,
          CustomerEmailAddress = customer.EmailAddress,
          EntrepreneurEmailAddress = entrepreneur.EmailAddress
        };
  }
}

您的结果类可以只是投影的最终形式，您不需要中间步骤：

public class Result
{
  public string Id { get; set; }
  public string CustomerEmailAddress { get; set; }
  public string EntrepreneurEmailAddress { get; set; }
}

如果你不想，你不必在索引中嵌套这个类。不管怎样都无所谓。您可以通过以下方式查询：

var items = session.Query<Result, OrdersApprovedBroadcastingData>();

或与

var items = session.Query<OrderDocument, OrdersApprovedBroadcastingData>().As<Result>();

虽然，对于第一种方式，约定往往是嵌套结果类，所以实际上是

var items = session.Query<OrderDocument.Result, OrdersApprovedBroadcastingData>();

请注意，在索引图中，我根本不包括任何属性。你问的都不需要。但是，如果您想在查询中添加 Where 或 OrderBy 子句，则您可能想要过滤或排序的任何字段都应该放在其中。

最后一件事 - 您使用的 OrderDocument、CustomerDocument、EntrepreneurDocument 约定有点奇怪。通常的约定只是订单、客户、企业家。将您的文档视为实体本身的持久形式。您使用的约定会起作用，只是不是通常使用的约定。