c#linq嵌套"条件/复合"分组

Question

我需要一些帮助编写LINQ查询,我试图做一些"条件/复合"分组.(不确定这是正确的术语).让我解释.

如果我有以下课程:

class Device
{
    int Id;
    string DeviceType;
    string DeeviceValue;
}

class Employee
{
    int Id;
    int SupervisorId;
    int CountryId;
    List<Device> Devices = new List<Device>();
}

从这里可以说我有这些对象:

List<Employee> Employees = new List<Employee>();
var emp1 = new Employee();
emp1.Id = 1;
emp1.CountryId = 1;
emp1.SupervisorId = 1;
Device dev1 = new Device();
dev1.Id = 1;
dev1.DeviceType = "Desk Phone";
dev1.DeviceValue = "132456789";
emp1.Devices.Add(dev1);
Employees.Add(emp1);

var emp2 = new Employee();
emp2.Id = 2;
emp2.CountryId = 1;
emp2.SupervisorId = 1;
Device dev2 = new Device();
dev2.Id = 2;
dev2.DeviceType = "Desk Phone";
dev2.DeviceValue = "123456789";
emp2.Devices.Add(dev2);
Device dev6 = new Device();
dev6.Id = 6;
dev6.DeviceType = "Conference Phone";
dev6.DeviceValue = "123456789";
emp2.Devices.Add(dev6);
Employees.Add(emp2);

var emp3 = new Employee();
emp3.Id = 3;
emp3.CountryId = 2;
emp3.SupervisorId = 1;
Device dev3 = new Device();
dev3.Id = 3;
dev3.DeviceType = "Desk Phone";
dev3.DeviceValue = "456789123";
emp3.Devices.Add(dev3);
Employees.Add(emp3);

var emp4 = new Employee();
emp4.Id = 4;
emp4.CountryId = 2;
emp4.SupervisorId = 4;
Device dev4 = new Device();
dev4.Id = 4;
dev4.DeviceType = "Desk Phone";
dev4.DeviceValue = "987123456";
emp4.Devices.Add(dev4);
Device dev5 = new Device();
dev5.Id = 5;
dev5.DeviceType = "Dealerboard";
dev5.DeviceValue = "987123456";
emp4.Devices.Add(dev5);
Employees.Add(emp4);

从这里我想创建一个按 - > SupervisorId - > CountryId - > DeviceType分组的查询.这很好,我有以下查询,它给了我想要的东西.

var result = Employees.SelectMany(e => e.Devices, (employee, devices) => new { employee, devices })
.GroupBy(e => new { e.devices.DeviceType, e.employee.SupervisorId, e.employee.CountryId })
.Select(e => new
    {
        DeviceType = e.Key.DeviceType,
        Supervisor = e.Key.SupervisorId,
        Country = e.Key.CountryId,
        employees = e
    });

我遇到的问题是我想创建一个可以包含多种设备类型的DeviceType组,"桌面电话"和"会议电话",而不是为每种设备类型设置一个单独的组.

编辑 - 完整性

上面的查询给出了以下结果

1. 设备类型 - >桌面电话
   • SupervisorId - > 1
   • CountryId - > 1
   • 员工 - >这将是Id = 1且Id = 2的员工
2. 设备类型 - >会议电话
   • SupervisorId - > 1
   • CountryId - > 1
   • 员工 - >这将是Id = 2的员工
3. 设备类型 - >桌面电话
   • SupervisorId - > 1
   • CountryId - > 2
   • 员工 - >这将是Id = 3的员工
4. 设备类型 - >桌面电话
   • SupervisorId - > 4
   • CountryId - > 2
   • 员工 - >这将是Id = 4的员工
5. 设备类型 - > Dealerboard
   • SupervisorId - > 4
   • CountryId - > 2
   • 员工 - >这将是Id = 4的员工

我追求的结果是:

1. 设备类型 - >台式电话和会议电话
   • SupervisorId - > 1
   • CountryId - > 1
   • 员工 - >这将是Id = 1且Id = 2的员工
2. 设备类型 - >桌面电话
   • SupervisorId - > 1
   • CountryId - > 2
   • 员工 - >这将是Id = 3的员工
3. 设备类型 - >桌面电话
   • SupervisorId - > 4
   • CountryId - > 2
   • 员工 - >这将是Id = 4的员工
4. 设备类型 - > Dealerboard
   • SupervisorId - > 4
   • CountryId - > 2
   • 员工 - >这将是Id = 4的员工

有没有办法通过LINQ执行此操作并修改我已有的查询？

任何帮助将非常感激.

皮特

Answer 1

创建一个字典，其中包含每个设备类型的键和其组的值，然后在分组时使用该字典

var deviceGroup = new Dictionary<string, string>() { { "Desk Phone", "Phone" }, { "Conference Phone", "Phone" } };

var result = Employees.SelectMany(e => e.Devices, (employee, devices) => new { employee, devices })
            .GroupBy(e => new { 
DeviceGroup = deviceGroup.ContainsKey(e.devices.DeviceType) ? 
              deviceGroup[e.devices.DeviceType] 
              : e.devices.DeviceType, 
e.employee.SupervisorId, e.employee.CountryId })
.Select(e => new
{
DeviceGroup = e.Key.DeviceGroup,

Supervisor = e.Key.SupervisorId,
Country = e.Key.CountryId,
employees = e
});