从2个可查询的结果中创建一个新的结果对象 [英] Creating a new result object from 2 iqueryable results
问题描述
我对linq有点生疏,但这正是我想要实现的目标。
I'm a bit rusty with linq, but this is what i'm trying to achieve.
IQueryable1 =>包含嵌套产品的项目列表(产品还包含groupingId字段
IQueryable1 => List of Items with nested Products (products also contain groupingId field
IQueryable2 =>具有分组ID的服务列表
IQueryable2 => List of Services with a grouping Id
我想返回一个新的查询结果,它几乎占用了第一个对象,并使用从query2获取的服务列表填充每个产品,并按分组ID进行过滤。
I want to return a new query result which pretty much takes the first object, and populates each product with a list of services taken from query2, filtered by the grouping id.
我想这样做而不在循环中迭代,这将触发查询执行但是想在第3个linq查询中执行它,该查询将在ToList上执行一个db调用()。
I want to do it without iterating in a loop which will trigger the queries to execute but want to do it in a 3rd linq query which will execute one db call on ToList().
类结构看起来像这样:
public class Item
{
public int Id {get;set;}
public string Name {get;set;}
public List<Product> Products {get;set;}
}
public class Product
{
public int Id {get;set;}
public string Name {get;set;}
public int GroupingId {get;set;}
public List<ServiceGroup> ServiceGroup {get;set;}
}
public class ServiceGroup
{
public int GroupingId{get;set;}
public List<Service> Services {get;set;}
}
public class Service
{
public int Id {get;set;}
public string Name {get;set;}
}
感谢任何人的帮助!
推荐答案
嗨 Milsnips,
基于你的代码,我不确定类结构是否正确。
我认为服务类应该包含GroupingId属性作为外键。
我做了一个简单的演示基础目前的阶级结构。您可以使用以下代码参考:
IEnumerable<Item> queryable1 = db.items.Include("Products").ToList();
IEnumerable<int> queryable2 = db.serviceGroups.Select(t=>t.GroupingId).ToList();
var result = queryable1.Select(t => new Item()
{
Id = t.Id,
Name = t.Name,
Products = t.Products.Where(x => queryable2.Contains(x.GroupingId)).ToList()
}).ToList();
如果您有任何问题,请随时告诉我。
最好的问候,
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