Question

我正在尝试按照https://docs.djangoproject.com/en/2.0/ref/contrib/postgres/operations/中的文档创建一个迁移，它实质上会在数据库上执行SQL语句CREATE EXTENSION IF NOT EXISTS hstore;。我尝试将名为create_extension_hstore.py的以下文件添加到migrations目录：

from django.db import migrations
from django.contrib.postgres.operations import CreateExtension


class Migration(migrations.Migration):
    operations = [CreateExtension(name='hstore')]

我的'心理模型'是因为Django从他们的dependencies推断出迁移的顺序而这个没有，所以应该先运行它。但是，当我尝试运行python manage.py makemigrations --merge时，我收到错误：

(venv) Kurts-MacBook-Pro:lucy-web kurtpeek$ python manage.py makemigrations --merge
(0.000) SELECT typarray FROM pg_type WHERE typname = 'citext'; args=None
(0.003) 
            SELECT c.relname, c.relkind
            FROM pg_catalog.pg_class c
            LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
            WHERE c.relkind IN ('r', 'v')
                AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
                AND pg_catalog.pg_table_is_visible(c.oid); args=None
(0.001) SELECT "django_migrations"."app", "django_migrations"."name" FROM "django_migrations"; args=()
Traceback (most recent call last):
  File "manage.py", line 29, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/base.py", line 330, in execute
    output = self.handle(*args, **options)
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/commands/makemigrations.py", line 142, in handle
    return self.handle_merge(loader, conflicts)
  File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/management/commands/makemigrations.py", line 272, in handle_merge
    raise ValueError("Could not find common ancestor of %s" % migration_names)
ValueError: Could not find common ancestor of {'0091_family_adopting_or_surrogate', 'create_extension_hstore'}

我该如何解决这个问题？我可以尝试将dependencies=['0001_initial']添加到Migration类，但这看起来有点武断，因为我真正想要的是先运行此迁移。

Answer 1

如果您希望在第一次生成的迁移之前运行，我认为您希望将此迁移添加到0001中的依赖项。

如果你现在只是需要hstore并且不需要它首先运行，你可以很容易地像正常一样添加data migration。

Answer 2

我最终使用HStoreField解决了更大的问题，而无需在数据库上手动运行CREATE EXTENSION hstore;，方法是将HStoreExtension()操作添加到operations 0001_initial.py迁移;另见https://docs.djangoproject.com/en/2.0/ref/contrib/postgres/operations/#create-postgresql-extensions。

Django“ValueErrror：找不到{migrations}的共同祖先”

2 个答案: