Связь многие ко многим (Entity Framework)

public class Student
{
    public Student() 
    {
        this.Courses = new HashSet<Course>();
    }
 
    public int StudentId { get; set; }
    [Required]
    public string StudentName { get; set; }
 
    public virtual ICollection<Course> Courses { get; set; }
}
        
public class Course
{
    public Course()
    {
        this.Students = new HashSet<Student>();
    }
 
    public int CourseId { get; set; }
    public string CourseName { get; set; }
 
    public virtual ICollection<Student> Students { get; set; }
}
 
public class StudentCourse
{
    public int Id { get; set; } 
    public int StudentRefId { get; set; }
    public int CourseRefId { get; set; }
    public DateTime Modified { get; set; }
}
 
public class SchoolDBContext : DBContext
{
    public SchoolDBContext() : base("SchoolDB-DataAnnotations")
    {
    }
 
    public DbSet<Student> Students { get; set; }
    
    public DbSet<Course> Courses { get; set; }
}

public class StudentCourse
{
    public int Id { get; set; } 
 
    public int StudentRefId { get; set; }
    [ForeignKey("StudentRefId ")]
    public Student Student { get;set; }
 
    public int CourseRefId { get; set; }
    [ForeignKey("CourseRefId ")]
    public Course Course {get;set;}
 
    public DateTime Modified { get; set; }
}
 
...
 
 
public class SchoolDBContext : DBContext
{
    public SchoolDBContext() : base("SchoolDB-DataAnnotations")
    {
    }
 
    public DbSet<Student> Students { get; set; }
    public DbSet<StudentCourse> StudentCourses { get; set; }
    public DbSet<Course> Courses { get; set; }
}