将DTO映射到实体模型

Question

我有一个基于Web的MVC 5项目。我首先使用ado实体模型数据库与EF6。 从我的模型我有以下T4生成的类

namespace Mvc5.Models
{
    using System;
    using System.Collections.Generic;

    public partial class Department
    {
        public Department()
        {
            this.Employee2 = new HashSet<Employee2>();
        }

        public int Id { get; set; }
        public string Name { get; set; }

        public virtual ICollection<Employee2> Employee2 { get; set; }
    }
}

和

namespace Mvc5.Models
{
    using System;
    using System.Collections.Generic;

    public partial class Employee2
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Gender { get; set; }
        public string City { get; set; }
        public Nullable<int> DepartmentId { get; set; }

        public virtual Department Department { get; set; }
    }
}

And I have a DTO Class not Mapped to Model

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Mvc5.Models
{
    public class DepartmentTotals
    {
        public string Name { get; set; }
        public int Totals { get; set; }
    }
}

在我的Controller中称为员工我有一个方法EmployeesByDepartment / 这将返回部门的员工视图

public ActionResult EmployeesByDepartment()
{
    var departmentTotals = db.Employee2.Include("Department")
                                       .GroupBy(x => x.Department.Name)
                                       .Select(y => new DepartmentTotals
                                       {
                                           Name = y.Key,
                                           Totals = y.Count()
                                       }).ToList();
    return View(departmentTotals);
}

问题是当我尝试使用DepartmentTotals作为模型

添加此方法的强类型视图时

我收到以下错误

Error: There was an error running the selected code generator Unable to retrieve metadata for DepartmentTotals

如何映射部门总计作为数据传输对象，我需要停止t4生成或使用旧版对象。所以我可以使用这个DTO查询数据库模型