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Я использую django в качестве своего бэкэнда, и он работал очень хорошо, но после того, как я попытался заменить text = models.TextField(blank=True, null=True) text = models.JSONField(blank=True, null=True) , но я получил текстовое поле, отображаемое в виде строки с косыми чертами

"text": "{"name": ["test", "test2"]}", в то время как поле стилей выглядит как json

         "style": {
            "borderRadius": "5px",
            "backgroundColor": "orange"
        },
  

несмотря на то, что они оба являются jsonfield.

models.py

 class elements(models.Model):
    tag = models.CharField(blank=True, null=True, max_length=20)

# it was # text = models.TextField(blank=True, null=True)
# now it is 
text = models.JSONField(blank=True, null=True)

    src = models.TextField(blank=True, null=True)

    style = models.JSONField(blank=True, null=True)

    main = models.ForeignKey(
        'self', null=True, blank=True, related_name="sub", on_delete=models.PROTECT)

    def __str__(self):
        return "<elements: {} {}>".format(self.tag, self.text, self.src, self.style)

    def __repr__(self):
        return self.__str__()
  

также после выполнения python manage.py makemigrations затем python manage.py migrate я получил сообщение об ошибке

 DETAIL:  Token "add" is invalid.
CONTEXT:  JSON data, line 1: add...
  

the full error

 Operations to perform:
  Apply all migrations: account, admin, auth, authtoken, contenttypes, myapp, sessions, sites
Running migrations:
  Applying myapp.0006_auto_20200905_1410...Traceback (most recent call last):
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
psycopg2.errors.InvalidTextRepresentation: invalid input syntax for type json
DETAIL:  Token "add" is invalid.
CONTEXT:  JSON data, line 1: add...


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

Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 245, in handle
    fake_initial=fake_initial,
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/migrations/executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/migrations/executor.py", line 227, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/migrations/operations/fields.py", line 236, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 572, in alter_field
    old_db_params, new_db_params, strict)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/postgresql/schema.py", line 168, in _alter_field
    new_db_params, strict,
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 726, in _alter_field
    params,
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 142, in execute
    cursor.execute(sql, params)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 98, in execute
    return super().execute(sql, params)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/Users/apple/Desktop/learning web stack from clonning notion.so/backend/env/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
django.db.utils.DataError: invalid input syntax for type json
DETAIL:  Token "add" is invalid.
CONTEXT:  JSON data, line 1: add...
  

• Примечание: я пытался удалить свои данные и переназначить, но не сработало
• Примечание: я использую PostgreSQL

Чтобы преобразовать текстовое поле в JSON-поле, вы можете использовать стратегию из 4 шагов, подобную этой:

• создайте новый столбец JSON в модели
• добавьте новую миграцию с помощью --empty и запустите функцию python с помощью RunPython, которая выбирает всю модель, загружает старое старое значение, преобразует его в объект JSON с помощью json.loads и сохраняет его в новом столбце
• удаление старого столбца текстового поля
• переименование нового столбца в исходное имя столбца