如何获取对父级和子级应用过滤器的子级集合

发布于 2024-12-11 08:00:32 字数 1428 浏览 0 评论 0原文

我正在使用 nHibernate 从 Sql Server 数据库检索订单集合（及其订单行）。

这是我的 ShipmentOrder 类：

public class ShipmentOrder
{
        private ICollection<ShipmentDetail> _ShipmentsDetails;

        public virtual ReadOnlyCollection<ShipmentDetail> ShipmentsDetails
        {
            get { return (new List<ShipmentDetail>(_ShipmentsDetails).AsReadOnly()); }
        }   
}

nHibernate 返回一个 IList，其中加载了所有详细信息 (ShipmentsDetails)（因为我渴望加载它们）。

现在，我想过滤 ShipmentOrder 和 ShipmentDetail 的集合并返回 ShipmentDetail 的集合。

我尝试过这样的事情：

IList<ShipmentOrder> Results;

// Fetch orders using nHibernate
Results = FetchOrders();

var shipmentLines = Results
    .Where(x => x.Company == "XXX" && x.OrderNumber == "111")
    .SelectMany(x => x.ShipmentsDetails)
    .Where(s => s.RowNumber == 1 && s.RowSeq == 0)
    .ToList();

但我意识到我获得了同一行的多个结果。

我已经像这样转换了 lamda 表达式：

var shipmentLines = Results
    .Where(x => x.Company == "XXX" && x.OrderNumber == "111")
    .SelectMany(x => x.ShipmentsDetails)
    .Where(s => s.RowNumber == 1 && s.RowSeq == 0)
    .Distinct()
    .ToList();

并且它工作正常。我想知道是否有更好的方法可以在没有 distinct 的情况下达到相同的结果。

更新：

我在这里使用 SelectMany，因为这是我发现将过滤器应用于子项（ShipmentsDetails）的唯一方法。

原文

I am using nHibernate to retrieve a collection of orders (and its order lines) from a Sql Server database.

This is my ShipmentOrder class:

public class ShipmentOrder
{
        private ICollection<ShipmentDetail> _ShipmentsDetails;

        public virtual ReadOnlyCollection<ShipmentDetail> ShipmentsDetails
        {
            get { return (new List<ShipmentDetail>(_ShipmentsDetails).AsReadOnly()); }
        }   
}

nHibernate returns a IList with all the details (ShipmentsDetails) loaded (since I Eager load them).

Now, I would like to filter my collection of ShipmentOrder and ShipmentDetail and get back a collection of ShipmentDetail.

I've tried something like this:

IList<ShipmentOrder> Results;

// Fetch orders using nHibernate
Results = FetchOrders();

var shipmentLines = Results
    .Where(x => x.Company == "XXX" && x.OrderNumber == "111")
    .SelectMany(x => x.ShipmentsDetails)
    .Where(s => s.RowNumber == 1 && s.RowSeq == 0)
    .ToList();

But I've realized that I obtain multiple results of the same line.

I've converted the lamda expression like this:

var shipmentLines = Results
    .Where(x => x.Company == "XXX" && x.OrderNumber == "111")
    .SelectMany(x => x.ShipmentsDetails)
    .Where(s => s.RowNumber == 1 && s.RowSeq == 0)
    .Distinct()
    .ToList();

and it works fine.
I was wondering if there's a better way to achieve the same result without the distinct.

UPDATE:

I am using SelectMany here cause this is the only way I've found to apply filters to children (ShipmentsDetails).

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