.Net核心:多对多关系Get操作

public class Student
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<StudentCourse> StudentCourses { get; set; }
}

public class Course
{
    public int Id { get; set; }
    public string Title { get; set; }
    public ICollection<StudentCourse> StudentCourses { get; set; }
}

public class StudentCourse
{
    public int StudentId { get; set; }
    public Student Student { get; set; }
    public int CourseId { get; set; }
    public Course Course { get; set; }
}

public class SchoolContext : DbContext
{
    public DbSet<Student> Students { get; set; }
    public DbSet<Course> Courses { get; set; }
    public DbSet<StudentCourse> StudentCourses { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<StudentCourse>()
            .HasKey(sc => new { sc.StudentId, sc.CourseId });

        modelBuilder.Entity<StudentCourse>()
            .HasOne(sc => sc.Student)
            .WithMany(s => s.StudentCourses)
            .HasForeignKey(sc => sc.StudentId);

        modelBuilder.Entity<StudentCourse>()
            .HasOne(sc => sc.Course)
            .WithMany(c => c.StudentCourses)
            .HasForeignKey(sc => sc.CourseId);
    }
}

using (var context = new SchoolContext())
{
    var studentCourses = context.Students
        .Where(s => s.Id == studentId)
        .SelectMany(s => s.StudentCourses.Select(sc => sc.Course))
        .ToList();
}

var studentWithCourses = context.Students
    .Include(s => s.StudentCourses).ThenInclude(sc => sc.Course)
    .FirstOrDefault(s => s.Id == studentId);