EF Code First导航属性一对一关系中注意点及配置方法

//学生
public class Student
    {
       [key]
        public int StId { get; set; }
        public int SocialSecurityNumber { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public virsual StPhoto Photo { get; set; }
    }
//学生图片
    public class StPhoto
    {
        [Key, ForeignKey("Student")]
        public int StId { get; set; }
        public byte[] Photo { get; set; }
        public string Caption { get; set; }
        public virsual  Student StudentInfo{ get; set; }
    }

modelBuilder.Entity<StPhoto>().HasRequired(p => p.StudentInfo).WithOptional(p => p.Photo);