C# 如何在实体框架中包含来自派生对象的集合

对不起，那个标题不太好。假设我有一些课程：

public abstract class Person {
    public int ID { get; set; }
}

public class Student : Person {
    public Student() {
        Grades = new List<Grades>();
    }
    public virtual ICollection<Grades> Grades { get; set; }
}

public class Teacher : Person {
    public string Class { get; set; }
}
public class Grades {
    public int Score { get; set; }
}

但我该怎么做：

db.People.where(p => p is Student).Include(s => s.Grades)

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不打开lazyloading？

您只需将Grades属性标记为非虚拟（删除虚拟关键字）即可为此禁用延迟加载。

您可以使用OfType按类型筛选，然后对其应用包含

var students = db.People.OfType<Student>().Include(s => s.Grades);

var students=db.People.OfType（）。包括（s=>s.Grades）；

var students = db.People.OfType<Student>().Include(s => s.Grades);