使用Heroku时，针对django_migrations关系的权限被拒绝。

Question

尝试在Heroku上使用Django进行数据库变更迁移时，出现以下错误信息：

psycopg2.ProgrammingError: permission denied for relation django_migrations

其他人已经通过授予适当的权限（例如Permission denied for relation）解决了此问题。不幸的是，我无法在Heroku免费版中授予权限或创建新用户。

我成功回滚了几个迁移，但最终遇到了这个错误：

django.db.utils.ProgrammingError: table "labs_branch_tests" does not exist

您无法迁移回到新的迁移。

---

关于权限被拒绝访问django_migrations表的完整回溯信息

  File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 330, in execute
    output = self.handle(*args, **options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 204, in handle
    fake_initial=fake_initial,
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 115, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 145, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 250, in apply_migration
    self.recorder.record_applied(migration.app_label, migration.name)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 73, in record_applied
    self.migration_qs.create(app=app, name=name)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/query.py", line 394, in create
    obj.save(force_insert=True, using=self.db)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/base.py", line 807, in save
    force_update=force_update, update_fields=update_fields)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/base.py", line 837, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/base.py", line 923, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/base.py", line 962, in _do_insert
    using=using, raw=raw)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/query.py", line 1076, in _insert
    return query.get_compiler(using=using).execute_sql(return_id)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1107, in execute_sql
    cursor.execute(sql, params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: permission denied for relation django_migrations

psycopg2.ProgrammingError的完整回溯信息：表“labs_branch_tests”不存在

  File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 330, in execute
    output = self.handle(*args, **options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 204, in handle
    fake_initial=fake_initial,
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 119, in migrate
    state = self._migrate_all_backwards(plan, full_plan, fake=fake)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 194, in _migrate_all_backwards
    self.unapply_migration(states[migration], migration, fake=fake)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/executor.py", line 264, in unapply_migration
    state = migration.unapply(state, schema_editor)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/migration.py", line 178, in unapply
    operation.database_backwards(self.app_label, schema_editor, from_state, to_state)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/operations/fields.py", line 95, in database_backwards
    schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 457, in remove_field
    return self.delete_model(field.remote_field.through)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 324, in delete_model
    "table": self.quote_name(model._meta.db_table),
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 120, in execute
    cursor.execute(sql, params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: table "labs_branch_tests" does not exist

- drpm

Answer 1

我通过在postgres终端中授权给用户来解决了这个问题。

首先通过Heroku CLI (heroku pg:psql) 连接到postgres。

虽然很复杂，但您可以通过在postgres终端中调用\c来获取您的Heroku postgres用户名。(输出的最后一行将是You are now connected to database DATABASE_NAME as user USERNAME。)

然后像其他人展示的那样授予权限：

GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public to USERNAME;
GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA public to USERNAME;
GRANT ALL PRIVILEGES ON ALL FUNCTIONS IN SCHEMA public to USERNAME;

- drpm

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这拯救了我的一天！;) 无论如何，我不明白与我最初尝试解决问题的方法(GRANT ALL PRIVILEGES ON DATABASE mydb TO myuser;)有什么区别？！幕后它难道不是做着完全相同的事情吗？！不过还是非常感谢。 - Felix Bayer

Answer 2

我的情况是因为我的免费数据库达到了行数限制，因此写入访问权限被撤销：

$ heroku pg:info
=== DATABASE_URL
Plan:                  Hobby-dev
Status:                Available
Connections:           0/20
PG Version:            10.4
[..]
Rows:                  11683/10000 (Write access revoked)
[..]

- Aur Saraf

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谢谢！我完全忘记了我有这个 :) 这个错误不是很明确。 - David Dahan

谢谢一年前的Aur！这确实是我的问题！ - Aur Saraf

Answer 3

对我来说，是的，你可以告诉我写入权限已被撤销。

$ heroku pg:info
...
Rows:                  11683/10000 (Write access revoked)

但我不想倒出整个数据库。相反，我使用了标识最大表的方法

$ heroku pg:psql
>  select
  table_name
  , pg_relation_size(quote_ident(table_name)) as "raw_size"
  , pg_size_pretty(pg_relation_size(quote_ident(table_name)) as "size"
from information_schema.tables                                                                                                                                                                                                              
where table_schema = 'public'                                                                                                                                                                                                               
order by "raw_size" desc;

然后我使用以下代码清空最大的表：

> delete from <table name>;

- Harry Moreno