Как настроить мою модель таким образом, чтобы сгенерированная миграция Django не приводила к ошибке? - PullRequest
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Как настроить мою модель таким образом, чтобы сгенерированная миграция Django не приводила к ошибке?

0 голосов
/ 16 апреля 2020

Я использую Django и Python 3.7. Когда я запускаю команду для генерации миграции ... 

(venv) localhost:web davea$ python manage.py makemigrations maps
Migrations for 'maps':
  maps/migrations/0003_auto_20200416_1017.py
    - Alter field name on cooptype
    - Alter unique_together for cooptype (0 constraint(s))

Сгенерированная миграция выглядит как ... 

# Generated by Django 2.0 on 2020-04-16 15:17

from django.db import migrations, models


class Migration(migrations.Migration):

    dependencies = [
        ('maps', '0002_auto_20200401_1440'),
    ]

    operations = [
        migrations.AlterField(
            model_name='cooptype',
            name='name',
            field=models.CharField(max_length=200, unique=True),
        ),
        migrations.AlterUniqueTogether(
            name='cooptype',
            unique_together=set(),
        ),
    ]

Однако запуск миграции приводит к ошибке ... 

(venv) localhost:web davea$ python manage.py migrate maps
System check identified some issues:

WARNINGS:
?: (mysql.W002) MySQL Strict Mode is not set for database connection 'default'
    HINT: MySQL's Strict Mode fixes many data integrity problems in MySQL, such as data truncation upon insertion, by escalating warnings into errors. It is strongly recommended you activate it. See: https://docs.djangoproject.com/en/2.0/ref/databases/#mysql-sql-mode
Operations to perform:
  Apply all migrations: maps
Running migrations:
  Applying maps.0003_auto_20200416_1017...Traceback (most recent call last):
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/cursors.py", line 209, in execute
    res = self._query(query)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/cursors.py", line 315, in _query
    db.query(q)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/connections.py", line 239, in query
    _mysql.connection.query(self, query)
MySQLdb._exceptions.OperationalError: (1061, "Duplicate key name 'maps_cooptype_name_78130e1f_uniq'")

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 "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 365, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/core/management/base.py", line 335, in execute
    output = self.handle(*args, **options)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 200, in handle
    fake_initial=fake_initial,
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/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/davea/Documents/workspace/chicommons/maps/web/venv/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/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/migrations/executor.py", line 244, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/migrations/migration.py", line 122, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/migrations/operations/fields.py", line 216, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 509, in alter_field
    old_db_params, new_db_params, strict)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 679, in _alter_field
    self.execute(self._create_unique_sql(model, [new_field.column]))
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 117, in execute
    cursor.execute(sql, params)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 100, in execute
    return super().execute(sql, params)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/cursors.py", line 209, in execute
    res = self._query(query)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/cursors.py", line 315, in _query
    db.query(q)
  File "/Users/davea/Documents/workspace/chicommons/maps/web/venv/lib/python3.7/site-packages/MySQLdb/connections.py", line 239, in query
    _mysql.connection.query(self, query)
django.db.utils.OperationalError: (1061, "Duplicate key name 'maps_cooptype_name_78130e1f_uniq'")

Мне неясно, как заставить Django генерировать миграцию, которая не приведет к ошибке. Рассматриваемые модели приведены ниже ... 

class CoopType(models.Model):
    name = models.CharField(max_length=200, null=False, unique=True)

    objects = CoopTypeManager()

...
class Coop(models.Model):
    objects = CoopManager()
    name = models.CharField(max_length=250, null=False)
    types = models.ManyToManyField(CoopType)
    address = AddressField(on_delete=models.CASCADE)
    enabled = models.BooleanField(default=True, null=False)
    phone = PhoneNumberField(null=True)
    email = models.EmailField(null=True)
    web_site = models.TextField()

Что я могу сделать, чтобы настроить свою модель или миграцию, чтобы либо я мог сгенерировать действительную модель для запуска, либо я мог исправить миграцию так, чтобы она работала и запуск "makemigrations myapp" не генерирует никаких новых миграций?

Ответы [ 2 ]

1 голос
/ 19 апреля 2020

Вам необходимо добавить init_command в строку подключения к базе данных: 

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.mysql',
    'NAME': 'my_database',
    'OPTIONS': {
        'init_command': 'SET innodb_strict_mode=1',
    },
}

}

Кроме того, после добавления удалите папку миграции из приложения и попробуйте команду makemigrations .

Подробнее об этом можно узнать в ссылке

0 голосов
/ 19 апреля 2020

Оператор AlterUniqueTogether должен выполняться перед оператором unique=True AlterField . Итак, измените порядок operations, как показано ниже, 

from django.db import migrations, models


class Migration(migrations.Migration):
    dependencies = [
        ('maps', '0002_auto_20200401_1440'),
    ]

    operations = [
        migrations.AlterUniqueTogether(
            name='cooptype',
            unique_together=set(),
        ),

        migrations.AlterField(
            model_name='cooptype',
            name='name',
            field=models.CharField(max_length=200, unique=True),
        ),

    ]
...