尝试获取StudentId=1的“分数”时出错

我有以下实体和数据库上下文类,

public class Grade
{
    public int Id { get; set; }
    public string GradeName { get; set; }

    public virtual ICollection<Student> Students { get; set; } = new HashSet<Student>();
}

public class Student
{
    public int Id { get; set; }
    public string StudentName { get; set; }
}



public class SchoolContext : DbContext
{
    public DbSet<Grade> Grades { get; set; }
    public DbSet<Student> Students { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer(@"Server=(localdb)\MSSQLLocalDB;Database=SchoolDB;Trusted_Connection=True;");
    }
}

在执行下面的代码时遇到下面的错误,这里需要做什么。谢谢

我在寻找解决方案,但不在学生课堂上添加年级属性

系统InvalidOperationException:“包含属性lambda表达式”x=>{from Student c in x.Student where([c].Id==u studentId_0)select[c]}无效。表达式应表示属性访问:“t=>t、 “我的财产”。要将在派生类型上声明的导航作为目标,请指定目标类型的显式类型lambda参数,例如“(派生d)=>d、 “我的财产”。有关包含相关数据的更多信息,请参阅 http://go.microsoft.com/fwlink/?LinkID=746393 .'

static void Main(string[] args)
    {
        var studentId = 1;

        var context = new SchoolContext();
        var data = context.Grades.Include(x => x.Students.Where(c => c.Id == studentId)).SingleOrDefault();
    }