Asp.net mvc ASP.NET MVC查找未决费用

我正在学习使用实体框架的ASP.NETMVC4（首先是数据库），遇到了一个我无法解决的问题

我有以下表格：

• 学生：存储学生信息
• 课程：存储在学院中运行的课程
• StudentCourse：存储哪个学生选择了什么课程
• 费用：存储学生提交的与StudentCourse对应的费用

现在，我不想显示课程名称、课程费用、提交的总费用以及学生的待定费用 我在项目中使用实体框架，并尝试执行如下查询：

var feeslist = entities.Fees
        .Where(m => m.StudentCourse.status=="pending")
        .GroupBy(m => m.StudentCourse.id)
        .Select(m => new { StudentCourseId = m.Key, SumOfFees = m.Sum(v => v.fees) });

我想获取课程对象而不是StudentCourseId，以便显示课程、课程费用以及学生提交的总费用

在这种情况下，我列出了所有四个类的内容：

学生

---

如果你想最终得到课程对象，你应该用

var courseList=entities.Courses.Where（…）

等东西开始你的查询，然后反向工作。感谢Elliot的快速回复，但是写什么。选择（）来获得课程对象？从域驱动的设计角度来看，这是完全错误的。这些数据结构源自关系范式。

public partial class Student
{
    public Student()
    {
        this.Leaves = new HashSet<Leave>();
        this.StudentCourses = new HashSet<StudentCourse>();
    }

    public int id { get; set; }
    public string first_name { get; set; }
    public string middle_name { get; set; }
    public string last_name { get; set; }
    public string password { get; set; }
    public string email { get; set; }
    public string gender { get; set; }
    public string facebook { get; set; }
    public string contact_number { get; set; }
    public string address { get; set; }
    public string admin { get; set; }
    public string college { get; set; }
    public string status { get; set; }
    public System.DateTime createdat { get; set; }
    public System.DateTime updatedat { get; set; }
    public string descripton { get; set; }

    public virtual ICollection<Leave> Leaves { get; set; }
    public virtual ICollection<StudentCourse> StudentCourses { get; set; }
}

public partial class Course
{
    public Course()
    {
        this.CourseContents = new HashSet<CourseContent>();
        this.StudentCourses = new HashSet<StudentCourse>();
    }

    public int id { get; set; }
    public string course_name { get; set; }
    public int course_fees { get; set; }
    public int duration { get; set; }
    public string admin { get; set; }
    public string status { get; set; }
    public System.DateTime createdat { get; set; }
    public System.DateTime updatedat { get; set; }

    public virtual ICollection<CourseContent> CourseContents { get; set; }
    public virtual ICollection<StudentCourse> StudentCourses { get; set; }
}

public partial class StudentCourse
{
    public StudentCourse()
    {
        this.Fees1 = new HashSet<Fee>();
        this.Issues = new HashSet<Issue>();
    }

    public int id { get; set; }
    public int student_id { get; set; }
    public int course_id { get; set; }
    public int fees { get; set; }
    public System.DateTime join_date { get; set; }
    public string admin { get; set; }
    public System.DateTime createdat { get; set; }
    public System.DateTime updatedat { get; set; }
    public string status { get; set; }

    public virtual Course Course { get; set; }
    public virtual ICollection<Fee> Fees1 { get; set; }
    public virtual ICollection<Issue> Issues { get; set; }
    public virtual Student Student { get; set; }
}

public partial class Fee
{
    public int id { get; set; }
    public int student_course_id { get; set; }
    public int fees { get; set; }
    public string admin { get; set; }
    public System.DateTime createdat { get; set; }
    public System.DateTime updatedat { get; set; }

    public virtual StudentCourse StudentCourse { get; set; }
}

var feeslist = entities.Fees
        .Where(m => m.StudentCourse.status=="pending")
        .GroupBy(m => m.StudentCourse.Course)
        .Select(m => new { Course = m.Key, SumOfFees = m.Sum(v => v.fees) });