复杂的 Django CheckContraint 不会迁移

如何解决复杂的 Django CheckContraint 不会迁移

我在运行包含有点复杂的 CheckConstraint 的 Django (2.2) 迁移时遇到问题，该迁移在 python 3.6.9 上运行。

底层数据库为 PostGIS 9.5。

模型：

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'
        )
    ),),...

还有很大的坏痕迹：

  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,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,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,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。 任何帮助表示赞赏

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

来自模型：

(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)
        )
    ),None)
            )
        )
    )
)

我将尝试验证这些在 PostgreSQL 中是否有效。

解决方法

结果是问题在于约束名称

正如一位同事所指出的：

我发现 '%(app_label)s' 和 '%(class)s' 已添加到 Django 3.0 中，而我们在 Django 2.2 上！

一旦我摆脱了这些，迁移就会正确运行。