static void ViewTest()
        {
            var str = "";

            using (var db = new SqliteDbContext())
            {
                var list = db.VStats.Where(p => p.CLASS_NAME == str && p.POINTS == 9).ToList();
                foreach (var item in list)
                {
                    Console.WriteLine($"{item.STUDENT_NAME}\t{item.CLASS_NAME}\t{item.SUBJECT_NAME}\t{item.POINTS}");
                }
            }
        }
 static void CountTest()
 {
     using (var db = new SqliteDbContext())
     {
         var l1 = db.Student.Join(db.Class,
                                  p => p.CLASS_ID,
                                  p => p.CLASS_ID,
                                  (pl, pr) => new { pl.CLASS_ID, pl.STUDENT_ID, pl.STUDENT_NAME, pr.CLASS_NAME });
         var l2 = db.Score.Join(db.Subject,
                                p => p.SUBJECT_ID,
                                p => p.SUBJECT_ID,
                                (pl, pr) => new { pl.SCORE_ID, pl.STUDENT_ID, pl.SUBJECT_ID, pl.POINTS, pr.SUBJECT_NAME });
         var l3 = l1.Join(l2,
                          p => p.STUDENT_ID,
                          p => p.STUDENT_ID,
                          (pl, pr) => new { pl.STUDENT_NAME, pl.CLASS_NAME, pr.SUBJECT_NAME, pr.POINTS });
         foreach (var item in l3)
         {
             Console.WriteLine($"{item.STUDENT_NAME} {item.CLASS_NAME} {item.SUBJECT_NAME} {item.POINTS}");
         }
         //db.JoinTable.Where(p => p.TEST_ID < 10000).ToList();
     }
 }