Question

我有 2 个列表，比如学生和成绩。两个列表都有共同的 stuID。

class Student
{
    public int stuID;
    public string Name;
    // other properties
}

class Grades
{
    public int stuID;
    public string Grade;
    // other properties
}

如何将结果合并到另一个新列表中，每个学生的所有成绩如下...

 public class StudentGradeDetails
    {
        public int stuID{ get; set; }
        public string Name{ get; set; }
        public GradeDetails[] gradeDetails { get; set; }
}

Answer 1

Traceback (most recent call last):
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: home_language

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\core\management\__init__.py", line 377, in execute
    django.setup()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\apps\config.py", line 211, in import_models
    self.models_module = import_module(models_module_name)
  File "c:\users\daisy\appdata\local\programs\python\python38\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\Daisy\OneDrive\Documents\Work\django\prjs\funnystore\mysite\home\models.py", line 29, in <module>
    for rs in llist:
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 276, in __iter__
    self._fetch_all()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 1261, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 57, in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\sql\compiler.py", line 1152, in execute_sql
    cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
    return super().execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: home_language

根据属性将列表对象从一个列表复制到另一个列表

1 个答案: