复杂的 Django CheckContraint 不会迁移

Question

我遇到了问题运行 Django (2.2) 迁移包含一个有点复杂的 CheckConstraint，运行 python 3.6.9。

底层数据库是 PostGIS 9.5。

模特：

class Subscription(BaseModel):
    class Meta:
        constraints = [
            models.CheckConstraint(name='%(app_label)s_%(class)s_valid_product', check=(
                (models.Q(variant_id__exact=None) & models.Q(product_id__exact=None)) |
                (~models.Q(variant_id__exact=None) & ~models.Q(product_id__exact=None))
            ))
        ]
    ...
    product_id = models.IntegerField()
    variant_id = models.IntegerField()

迁移：

...
migrations.AddConstraint(
    model_name='subscription',
    constraint=models.CheckConstraint(
        name='%(app_label)s_%(class)s_valid_product',
        check=models.Q(
            models.Q(
                models.Q(variant_id__exact=None),
                models.Q(product_id__exact=None)
            ),
            models.Q(
                models.Q(_negated=True, variant_id__exact=None),
                models.Q(_negated=True, product_id__exact=None)
            ),
            _connector='OR'
        )
    ),
),
...

还有大坏道：

  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python3.6/site-packages/django/core/management/base.py", line 323, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python3.6/site-packages/django/core/management/base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 234, in handle
    fake_initial=fake_initial,
  File "/usr/local/lib/python3.6/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 "/usr/local/lib/python3.6/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 "/usr/local/lib/python3.6/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python3.6/site-packages/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python3.6/site-packages/django/db/migrations/operations/models.py", line 827, in database_forwards
    schema_editor.add_constraint(model, self.constraint)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 345, in add_constraint
    self.execute(sql)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 137, in execute
    cursor.execute(sql, params)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 99, in execute
    return super().execute(sql, params)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 67, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 76, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
TypeError: tuple indices must be integers or slices, not str

迁移是自动生成的。我只是格式化它看起来更漂亮。感谢任何帮助

编辑：我注意到那些 Q-expressions 的 __str__ 表示不同：

来自模特：

(OR: 
    (AND: 
        ('variant_id__exact', None), 
        ('product_id__exact', None)
    ), 
    (AND: 
        (NOT 
            (AND: 
                ('variant_id__exact', None)
            )
        ), 
        (NOT 
            (AND: 
                ('product_id__exact', None)
            )
        )
    )
)

来自迁移：

(OR: 
    (AND: 
        (AND: 
            ('variant_id__exact', None)
        ), 
        (AND: 
            ('product_id__exact', None)
        )
    ), 
    (AND: 
        (NOT 
            (AND: 
                ('variant_id__exact', None)
            )
        ), 
        (NOT 
            (AND: 
                ('product_id__exact', None)
            )
        )
    )
)

我将尝试验证这些在 PostgreSQL 中是否有效。

Answer 1

原来问题是约束名称

正如一位同事指出的那样：

Something I've found '%(app_label)s' and '%(class)s' were added on Django 3.0, and we are on Django 2.2!

一旦我摆脱了那些，迁移运行就正确了。

复杂的 Django CheckContraint 不会迁移

Complex Django CheckContraint won't migrate

python

django

check-constraints