Django迁移失败,因为表已经存在?

时间:2015-10-22 03:03:46

标签: django postgresql

所以我改变了一些模型,数据结构发生了巨大变化,导致迁移失败。我清除了数据库中受影响的表,删除了所有迁移文件,然后再次尝试迁移。

它为所有表(甚至是我在数据库中留下的表)进行了迁移,当我尝试迁移时出现此错误:

Operations to perform:
  Apply all migrations: study
Running migrations:
  Rendering model states... DONE
  Applying study.0001_initial...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 393, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 444, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/migrate.py", line 222, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 110, in migrate
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 148, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/migration.py", line 115, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/operations/models.py", line 59, in database_forwards
    schema_editor.create_model(model)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 286, in create_model
    self.execute(sql, params or None)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 111, in execute
    cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 62, in execute
    return self.cursor.execute(sql)
django.db.utils.ProgrammingError: relation "study_language" already exists

如果我进入迁移文件并删除尝试迁移现有表的位置,我会收到此错误...

Operations to perform:
  Apply all migrations: study
Running migrations:
  Rendering model states... DONE
  Applying study.0001_initial...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 393, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 444, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/migrate.py", line 222, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 110, in migrate
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 148, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/migration.py", line 115, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/operations/models.py", line 59, in database_forwards
    schema_editor.create_model(model)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 236, in create_model
    definition, extra_params = self.column_sql(model, field)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 135, in column_sql
    db_params = field.db_parameters(connection=self.connection)
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 2003, in db_parameters
    return {"type": self.db_type(connection), "check": []}
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1994, in db_type
    rel_field = self.related_field
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1897, in related_field
    return self.foreign_related_fields[0]
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1631, in foreign_related_fields
    return tuple(rhs_field for lhs_field, rhs_field in self.related_fields)
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1618, in related_fields
    self._related_fields = self.resolve_related_fields()
  File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1603, in resolve_related_fields
    raise ValueError('Related model %r cannot be resolved' % self.rel.to)
ValueError: Related model u'study.Language' cannot be resolved

如何在不删除我在db中留下的所有表的情况下使其工作?

1 个答案:

答案 0 :(得分:0)

对我有用的是我在models.py中注释了db中没有的所有迁移。然后我再次清理了迁移文件夹并运行命令...

$ python manage.py makemigrations
$ python manage.py migrate appname --fake-initial

哪个顺利进行然后我取消注释我想要添加到数据库并运行正常迁移的模型......

$ python manage.py makemigrations
$ python manage.py migrate

一切顺利