C# 我如何找到所有兄弟姐妹'；儿童档案？

我被卡住了，需要一个linq声明来完成以下任务

情况： 商店有一个收款部门，有一个收款订单

  StoreID:1
     DepartmentID:D1,
        OrderID:O1,
        OrderID:O2,
        OrderID:O3,
     DepartmentID:D2,
        OrderID:O4,
        OrderID:O5
     DepartmentID:D3,
        OrderID:O6,
        OrderID:O7

如果给定部门ID，请查找与其关联的商店。通过该商店获取与该商店相关的所有部门的所有订单

如果我有一个部门的id，在上面的例子中说D2。我要D2商店所有相关部门的所有订单

---

linq声明会是什么样子

假设您有这样一个类模型：

public class Store
{
  public string StoreID{get;set;}
  public IList<Department> Departments{get;set;}
}

public class Department
{
  public string DepartmentID{get;set;}
  public Store Store{get;set;}
  public IList<Order> Orders{get;set;}
}

public class Order
{
  public string OrderID{get;set;}
  public Department Department{get;set;}
}

---

您也可以这样做。您可以在LinqPad中验证这一点，以进行概念验证

void Main()
{
    var storeDepartments = new List<Department>();

    storeDepartments.Add(new Department { DepartmentId= 1, OrdersId= new List<int>(){1,2,3}});
    storeDepartments.Add(new Department { DepartmentId= 2, OrdersId= new List<int>(){4,5}});
    storeDepartments.Add(new Department { DepartmentId= 3, OrdersId= new List<int>(){6,7}});

    var stores = new List<Store>();

    var myStore = new Store {
        StoreId= 1,
        Departments= storeDepartments
    };

    stores.Add(myStore);

    var store = stores.Find(s => s.Departments.First(d => d.DepartmentId == 2) != null);

    var orders = store.Departments.SelectMany(d => d.OrdersId).ToList();

    orders.Dump();
}

// Define other methods and classes here

public class Store {
    public int StoreId { get; set; }
    public List<Department> Departments { get; set; }
}

public class Department {
    public int DepartmentId { get; set; }
    public List<int> OrdersId { get; set; }
}

void Main（）
{
var storeDepartments=新列表（）；
Add（新部门{DepartmentId=1，OrdersId=newlist（）{1,2,3}）；
Add（新部门{DepartmentId=2，OrdersId=newlist（）{4,5}）；
Add（新部门{DepartmentId=3，OrdersId=newlist（）{6,7}）；
var stores=新列表（）；
var myStore=新商店{
StoreId=1，
部门=仓库部门
};
添加（myStore）；
var store=stores.Find（s=>s.Departments.First（d=>d.DepartmentId==2）！=null）；
var orders=store.Departments.SelectMany（d=>d.OrdersId.ToList（）；
orders.Dump（）；
}
//在此处定义其他方法和类
公共类商店{
public int StoreId{get；set；}
公共列表部门{get；set；}
}
公共课系{
public int DepartmentId{get；set；}
公共列表顺序SID{get；set；}
}

同一部门是否与多个门店相关？您可以添加任何扩展的数据集示例。不，每个部门仅与一个商店相关。

void Main()
{
    var storeDepartments = new List<Department>();

    storeDepartments.Add(new Department { DepartmentId= 1, OrdersId= new List<int>(){1,2,3}});
    storeDepartments.Add(new Department { DepartmentId= 2, OrdersId= new List<int>(){4,5}});
    storeDepartments.Add(new Department { DepartmentId= 3, OrdersId= new List<int>(){6,7}});

    var stores = new List<Store>();

    var myStore = new Store {
        StoreId= 1,
        Departments= storeDepartments
    };

    stores.Add(myStore);

    var store = stores.Find(s => s.Departments.First(d => d.DepartmentId == 2) != null);

    var orders = store.Departments.SelectMany(d => d.OrdersId).ToList();

    orders.Dump();
}

// Define other methods and classes here

public class Store {
    public int StoreId { get; set; }
    public List<Department> Departments { get; set; }
}

public class Department {
    public int DepartmentId { get; set; }
    public List<int> OrdersId { get; set; }
}