向现有模型添加新字段 - django.db.utils.ProgrammingError：列{field}不存在

Question

models.朋友

我有一个Scorecard模型，它有一个名为Account的另一个模型的ManyToManyField：

class Scorecard(models.Model):

    ....
    name = models.CharField(max_length=100)
    accounts = models.ManyToManyField(Account)
    ...

    def __str__(self):
        return self.name

我的Account类目前有四个字段（account_name，adwords_account_id，bingads_account_id，label）。

class Account(models.Model):

    account_name = models.CharField(max_length=100)
    adwords_account_id = models.CharField(max_length=10, blank=True)
    bingads_account_id = models.CharField(max_length=15, blank=True)
    # gemini_account_id = models.CharField(max_length=15, blank=True)
    label = models.CharField(max_length=30, blank=True)

    def __str__(self):
        return self.account_name

请注意，字段gemini_account_id已注释掉。我想将此字段添加到模型中。

如果我留下gemini_account_id注释掉和runserver，一切正常。

如果我然后取消注释gemini_account_id并做python manage.py makemigrations

(venv) C:\Django\scorecard>python manage.py makemigrations

完全错误

Traceback (most recent call last):
  File "C:\Django\venv\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: column scorecards_account.gemini_account_id does not exist
LINE 1: ...t_id", "scorecards_account"."bingads_account_id", "scorecard...
                                                             ^


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

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Django\venv\lib\site-packages\django\core\management\__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "C:\Django\venv\lib\site-packages\django\core\management\__init__.py", line 347, in execute
    django.setup()
  File "C:\Django\venv\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Django\venv\lib\site-packages\django\apps\registry.py", line 120, in populate
    app_config.ready()
  File "C:\Django\venv\lib\site-packages\django\contrib\admin\apps.py", line 23, in ready
    self.module.autodiscover()
  File "C:\Django\venv\lib\site-packages\django\contrib\admin\__init__.py", line 26, in autodiscover
    autodiscover_modules('admin', register_to=site)
  File "C:\Django\venv\lib\site-packages\django\utils\module_loading.py", line 47, in autodiscover_modules
    import_module('%s.%s' % (app_config.name, module_to_search))
  File "C:\Django\venv\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "C:\Django\scorecard\scorecards\admin.py", line 2, in <module>
    from scorecards.forms import (ScorecardAdminForm, AccountAdminForm, ReportTypeAdminForm,
  File "C:\Django\scorecard\scorecards\forms.py", line 5, in <module>
    class ScorecardAdminForm(forms.ModelForm):
  File "C:\Django\scorecard\scorecards\forms.py", line 7, in ScorecardAdminForm
    class Meta:
  File "C:\Django\scorecard\scorecards\forms.py", line 15, in Meta
    attrs={'class': 'wide-select'}),
  File "C:\Django\venv\lib\site-packages\django\forms\widgets.py", line 558, in __init__
    self.choices = list(choices)
  File "C:\Django\venv\lib\site-packages\django\db\models\query.py", line 272, in __iter__
    self._fetch_all()
  File "C:\Django\venv\lib\site-packages\django\db\models\query.py", line 1179, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "C:\Django\venv\lib\site-packages\django\db\models\query.py", line 54, in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
  File "C:\Django\venv\lib\site-packages\django\db\models\sql\compiler.py", line 1063, in execute_sql
    cursor.execute(sql, params)
  File "C:\Django\venv\lib\site-packages\django\db\backends\utils.py", line 100, in execute
    return super().execute(sql, params)
  File "C:\Django\venv\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:\Django\venv\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Django\venv\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Django\venv\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Django\venv\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: column scorecards_account.gemini_account_id does not exist
LINE 1: ...t_id", "scorecards_account"."bingads_account_id", "scorecard...
                                                             ^

好的。所以这告诉我数据库中不存在gemini_account_id列。我对此的反应是“那是因为我试图添加它！”。我以为makemigrations帮助我这样做？

将新字段添加到现有模型（Account）的另一个模型（Scorecard）的“ManyToManyField”中，适当的操作步骤是什么？

我的数据库是PostgreSQL。

我试过了什么：

1. python manage.py makemigrations scorecards：与上面相同的错误
2. 重命名了迁移文件夹，使用init.py创建了空文件夹：与上面相同的错误。
3. 我经历了每次迁移，每次删除一次并运行makemigrations：每次都出现与上面相同的错误

我看过的其他帖子：

This one似乎是最接近的，但建议是“迁移落后于该特定模型”。

更新：这是forms.py ScorecardAdminForm：

class ScorecardAdminForm(forms.ModelForm):

    class Meta:

        model = Scorecard
        fields = '__all__'
        #fields = ('name', 'accounts', 'report_type', 'date_range')
        widgets = {
            'name': forms.TextInput(attrs={'class': 'wide-select'}),
            'accounts': forms.SelectMultiple(choices=Account.objects.all(),
                                             attrs={'class': 'wide-select'}),
            'report_type': forms.Select(attrs={'class': 'wide-select'}),
            'date_range': forms.Select(attrs={'class': 'wide-select'}),
            'time_segment': forms.Select(attrs={'class': 'wide-select'})
        }

    def clean(self):
        cleaned_data = super().clean()
        date_range = cleaned_data.get('date_range')
        start_date = cleaned_data.get('start_date')
        end_date = cleaned_data.get('end_date')

        if date_range == 'CUSTOM_DATE':
            if start_date is None or end_date is None:
                raise ValidationError(
                    "Start or end can't be left blank "
                    "when report type is custom date range."
                )

我想通过在admin.py和forms.py中注释掉所有内容然后跟随this answer，我确实得到了一切。是我的ScorecardAdminForm的原因？也许提出ValidationError部分？对不起，我是一只迷失的小羊羔。

Answer 1

该字段通过管理表单引用。从ScorecardAdminForm中删除引用并首先进行迁移。