I started using Flask-Migrate today and installed it on a test project.
However i am getting following error:
alembic.util.exc.CommandError: Can't locate revision identified by
'e39d16e62810'
Steps to reproduce:
run "python create_db.py"
run "flask db init"
add column "name" to Entry-model
run "flask db migrate"
EDIT:
After removing migrations directory and repeating the process i am getting the same error after running "flask db migrate".
I also tried using a manage.py file with flask-script --> same issue
Error:
(venv_mentz) H:\Flask-API-Test>python manage.py db migrate
INFO [alembic.runtime.migration] Context impl SQLiteImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
Traceback (most recent call last):
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 143, in _catch_revision_errors
yield
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 206, in get_revisions
return self.revision_map.get_revisions(id_)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 299, in get_revisions
return sum([self.get_revisions(id_elem) for id_elem in id_], ())
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 299, in <listcomp>
return sum([self.get_revisions(id_elem) for id_elem in id_], ())
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 304, in get_revisions
for rev_id in resolved_id)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 304, in <genexpr>
for rev_id in resolved_id)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 362, in _revision_for_ident
resolved_id)
alembic.script.revision.ResolutionError: No such revision or branch 'e39d16e62810'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 14, in <module>
manager.run()
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\flask_script\__init__.py", line 417, in run
result = self.handle(argv[0], argv[1:])
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\flask_script\__init__.py", line 386, in handle
res = handle(*args, **config)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\flask_script\commands.py", line 216, in __call__
return self.run(*args, **kwargs)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\flask_migrate\__init__.py", line 197, in migrate
version_path=version_path, rev_id=rev_id)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\command.py", line 176, in revision
script_directory.run_env()
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 425, in run_env
util.load_python_file(self.dir, 'env.py')
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\util\pyfiles.py", line 81, in load_python_file
module = load_module_py(module_id, path)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\util\compat.py", line 83, in load_module_py
spec.loader.exec_module(module)
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
File "migrations\env.py", line 87, in <module>
run_migrations_online()
File "migrations\env.py", line 80, in run_migrations_online
context.run_migrations()
File "<string>", line 8, in run_migrations
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\runtime\environment.py", line 836, in run_migrations
self.get_context().run_migrations(**kw)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\runtime\migration.py", line 321, in run_migrations
for step in self._migrations_fn(heads, self):
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\command.py", line 156, in retrieve_migrations
revision_context.run_autogenerate(rev, context)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\autogenerate\api.py", line 415, in run_autogenerate
self._run_environment(rev, migration_context, True)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\autogenerate\api.py", line 425, in _run_environment
if set(self.script_directory.get_revisions(rev)) != \
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 206, in get_revisions
return self.revision_map.get_revisions(id_)
File "c:\users\marschall\appdata\local\programs\python\python36-32\Lib\contextlib.py", line 100, in __exit__
self.gen.throw(type, value, traceback)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 174, in _catch_revision_errors
compat.raise_from_cause(util.CommandError(resolution))
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\util\compat.py", line 194, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=exc_value)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\util\compat.py", line 187, in reraise
raise value.with_traceback(tb)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 143, in _catch_revision_errors
yield
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\base.py", line 206, in get_revisions
return self.revision_map.get_revisions(id_)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 299, in get_revisions
return sum([self.get_revisions(id_elem) for id_elem in id_], ())
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 299, in <listcomp>
return sum([self.get_revisions(id_elem) for id_elem in id_], ())
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 304, in get_revisions
for rev_id in resolved_id)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 304, in <genexpr>
for rev_id in resolved_id)
File "H:\Flask-API-Test\venv_mentz\lib\site-packages\alembic\script\revision.py", line 362, in _revision_for_ident
resolved_id)
alembic.util.exc.CommandError: Can't locate revision identified by 'e39d16e62810'
My file structure looks like this:
app
-- views
----- __init__.py
----- main.py
-- __init__.py
-- config.py
-- models.py
instance
-- __init__.py
-- config.py
create_db.py
dev.db
run.py
My app factory:
from flask import Flask
from instance.config import app_config
from flask_migrate import Migrate
def create_app(config_name):
""" Creates a runnable app.
This app will be using the config with name "config_name".
"""
app = Flask(__name__)
# Loading the the config from instance folder with name "config_name"
app.config.from_object(app_config[config_name])
# Loading generic config from 'config.py'
app.config.from_pyfile('config.py')
# Registering this app at db
from app.models import db
db.init_app(app)
migrate = Migrate(app, db)
from app import models, views
return app
My run.py:
""" This script runs a the app with the given configuration. """
from app import create_app
# Configuration used to run the app
config_name = 'dev'
# Creating the app by using the required configuration
app = create_app(config_name)
if __name__ == '__main__':
app.run()
And my create_db.py file to create the database using models.py:
""" This script creates the database defined in app.models. """
from app import create_app
app = create_app('dev')
from app.models import db
# Telling SQLAlchemy what app should be used as the database model
with app.app_context():
db.create_all()
This is my models.py:
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class Entry(db.Model):
__tablename__ = 'Entries'
layer_id = db.Column(db.Integer, primary_key=True)
def __repr__(self):
return "ID: {}; text: {}".format(self.layer_id, self.text)
EDIT: manage.py:
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
from app import create_app
from app import models
from app.models import db
app = create_app('dev')
migrate = Migrate(app, db)
manager = Manager(app)
manager.add_command('db', MigrateCommand)
if __name__ == '__main__':
manager.run()
you delete the migration directory but the version has been saved in the database, so you have to delete the version info in the dabase,
run
delete from alembic_version;
in mysql shell.
As suggested by #mirekphd, If this is a developing environment or a single app for test, just delete it, Else BACKUP the data in the table.
I tried this on flask and it worked:
python app.py db revision --rev-id e39d16e62810
python app.py db migrate
python app.py db upgrade
In my case I have accidentally deleted the most recent migration file but the alembic version (alembic_version) table refers to the deleted version.
So instead of droping the entire database, you can change the version_num field in the alembic_version table.
Following steps worked for me:
Find the head using db history
Update the version_num field to the head version.
run migrate using db migrate
upgrade the database db upgrade
Most of the time this happens, if you are at the development stage where you don't have much data to loose, you can drop the database and create a fresh one, alternatively, you can delete the migrations and begin the whole cycle again, for sqlite, it is all about deleting the sqlite file in your application, and beginning this cycle again. I hope to find the best solution to this verry soon.
In my case, I have accidentally deleted the most recent migration file but the alembic version (alembic_version) table refers to the deleted version.
I tried the following:
flask db revision --rev-id [revision-id]
flask db migrate
flask db upgrade
My problem was that another flask app was already connected to the same database, so I just created a new database, and changed:
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:root#127.0.0.1:3306/newDataBaseName'
Delete the history entry from the database will solve the issue.
Error: alembic.util.exc.CommandError: Can't locate revision identified by 'e39d16e62810'
select * from alembic_version where version_num='e39d16e62810'
Option 1: Update the record with your latest revision id
update alembic_version set version_num='<your_version_num>' where version_num='e39d16e62810'
Option 2: Delete this record:
delete from alembic_version where version_num='e39d16e62810'
For my case reason for the error was the relative path to sqlite db.
Fixed it by specifying the absolute path
app.config['SQLALCHEMY_DATABASE_URI'] = f"sqlite:///{os.path.join(os.path.dirname(__file__), os.path.pardir, 'db.sqlite')}"
Yet another cause of problems - making two flask projects in the same virtual environment.
I tried to make fake twin project for performance testing.
copied crucial parts of the original project
created new database
made changes in configuration file to point to new database
flask db init,
flask db migrate
got this error at first migration.
Then I did only one thing - created new python environment for this twin project - and error disappeared.
PS. Maybe it is possible to create two flask projects in the same environment, but I was not able to find solution.
In my case, since I was in the initial phase, I had the luxury of deleting the database file directly i.e. in my project folder there was a .sqlite file, so I deleted it by right-clicking it.
But please keep in mind that I was in the initial phase, so I won't suggest this if you are
not in the starting phase.
I had the same error message but in my case it's because I used wrong database name in the connection string. Check your connection string
Error Message:
ERROR [root] Error: Can't locate revision identified by 'a80ab7ca5e1a'
Reason:
My connection string was:
mysql+pymysql://kaunda:kaunda#localhost:3306/smis
Instead of
mysql+pymysql://kaunda:kaunda#localhost:3306/WorkFolder
The revision identified by "a80ab7ca5e1a" belongs to the database "smis" not "WorkFolder"
Make sure you set FLASK_APP=app.py on windows or export FLASK_APP=app.py on MAC before running flask db init, then flask db migrate -m "message" and flask db upgrade. You can check this link for more info https://pypi.org/project/Flask-Migrate/
I am trying to test my Django test files separately, one by one, as ./manage.py test freezes for 5secs after each run due to heavy apps.
This is my test (not even a test yet though, just playing with requests):
if __name__ == "__main__":
import unittest
# manually get all the django stuff into memory if file is called directly
import os,sys
TEST_ROOT = os.path.realpath(os.path.dirname(__file__))
PROJ_AND_TEST_ROOT = os.path.dirname(os.path.dirname(TEST_ROOT))
PROJECT_ROOT = os.path.join(PROJ_AND_TEST_ROOT, 'the_game')
sys.path.append(PROJECT_ROOT)
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "the_game.settings")
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
from django.test import TestCase, RequestFactory
from django.contrib.auth.models import User
from interface.views import bets
class ViewTests(TestCase):
def test_bets_view(self):
request_factory=RequestFactory()
request=request_factory.get('/')
user = User.objects.create_user('testname','test#na.me','testname')
request.user=user
response=bets(request)
print response
if __name__ == "__main__":
unittest.main()
However, running this I get the following:
======================================================================
ERROR: test_bets_view (__main__.ViewTests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/test/testcases.py", line 182, in __call__
self._pre_setup()
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/test/testcases.py", line 754, in _pre_setup
self._fixture_setup()
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/test/testcases.py", line 887, in _fixture_setup
if not connections_support_transactions():
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/test/testcases.py", line 874, in connections_support_transactions
for conn in connections.all())
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/test/testcases.py", line 874, in <genexpr>
for conn in connections.all())
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/utils/functional.py", line 55, in __get__
res = instance.__dict__[self.func.__name__] = self.func(instance)
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/db/backends/__init__.py", line 782, in supports_transactions
self.connection.leave_transaction_management()
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/db/backends/__init__.py", line 338, in leave_transaction_management
if managed == self.get_autocommit():
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/db/backends/__init__.py", line 345, in get_autocommit
self.ensure_connection()
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/db/backends/__init__.py", line 133, in ensure_connection
self.connect()
File "/Users/1111/.virtualenvs/the_game/lib/python2.7/site-packages/django/db/utils.py", line 86, in __exit__
db_exc_type = getattr(self.wrapper.Database, dj_exc_type.__name__)
AttributeError: 'DatabaseWrapper' object has no attribute 'Database'
The project itself works perfectly without errors (./manage.py runserver), as do django tests (./manage.py test ../tests).
How can I fix this?
p.s. This is not a duplicate of this question. Its author had problems with standard Django testing, while it works fine for my project. My trouble is with third-party testing.
Unfortunately, what you're doing is not quite enough to initialize django's settings system. You can try this:
from django.core.management import setup_environ
from mysite import settings
setup_environ(settings)
Or you could look into writing a custom managment command (which will have the settings system initialized already) which calls the test runner.
I have the following very simple app:
from lib.flask import Flask
from lib.flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class TestResource(Resource):
def get(self):
return {"a":"b","c":"d"}
api.add_resource(TestResource, "/")
When I run this, I get the following Exception:
Traceback (most recent call last):
File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/runtime/wsgi.py", line 266, in Handle
result = handler(dict(self._environ), self._StartResponse)
File "/Users/me/dev/project/src/main.py", line 22, in do_in_request
app(*args, **kwargs)
File "/Users/me/dev/project/src/lib/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/Users/me/dev/project/src/lib/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/Users/me/dev/project/src/lib/flask_restful/__init__.py", line 249, in error_router
if self._has_fr_route():
File "/Users/me/dev/project/src/lib/flask_restful/__init__.py", line 230, in _has_fr_route
if self._should_use_fr_error_handler():
File "/Users/me/dev/project/src/lib/flask_restful/__init__.py", line 211, in _should_use_fr_error_handler
adapter = self.app.create_url_adapter(request)
File "/Users/me/dev/project/src/lib/flask/app.py", line 1601, in create_url_adapter
return self.url_map.bind_to_environ(request.environ,
File "/Users/me/dev/project/src/lib/werkzeug/local.py", line 338, in __getattr__
return getattr(self._get_current_object(), name)
File "/Users/me/dev/project/src/lib/werkzeug/local.py", line 297, in _get_current_object
return self.__local()
File "/Users/me/dev/project/src/lib/flask/globals.py", line 20, in _lookup_req_object
raise RuntimeError('working outside of request context')
RuntimeError: working outside of request context
So I tried to put my entire app into what I thought would be the request context. In the code above, both the Flask object and the Api object are being instantiated once, and can be called by the server multiple times. From the traceback, it looks like the instantiation should happen within a request context, so I wrapped it like this:
def do_in_request(*args, **kwargs):
from lib.flask import Flask
from lib.flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class TestResource(Resource):
def get(self):
return {"a":"b","c":"d"}
api.add_resource(TestResource, "/")
app(*args, **kwargs)
app = do_in_request
That still raises the same error. What's going on, what do they mean by 'request context', and how do I fix this?
I started from scratch using the App Engine Flask Skeleton and added flask-restful as a dependency in requirements.txt and then just added more or less the code you have above and it worked without an issue. I added the repository to my github here if you want to use it - you can see the changes I made to the skeleton in this commit.
I'm not sure why your example isn't working, but one thing I noticed that could be causing issues is that you're doing from lib.flask .... It seems your third-party packages live in lib and you haven't necessarily "lifted" lib into your sys.path. The skeleton includes a vendoring library that makes sure that this is handled properly. It might be a potential source of the problem.
Either way, I hope the forked skeleton can help you get up and running.
I'm having some trouble implementing the Cork library with a Bottle app. I've tried setting up the example app, and I made some minor modifications to get it to run in an WSGI container. The main change is that I changed this:
if __name__ == "__main__":
main()
to this:
application = default_app()
When I authenticate with the admin user, I get the following:
Traceback (most recent call last):
File "/path_to_app/lib/python2.7/bottle-0.11.4-py2.7.egg/bottle.py", line 763, in _handle
return route.call(**args)
File "/path_to_app/lib/python2.7/bottle-0.11.4-py2.7.egg/bottle.py", line 1572, in wrapper
rv = callback(*a, **ka)
File "/path_to_app/cork-example/simple_webapp.py", line 47, in login
aaa.login(username, password, success_redirect='/', fail_redirect='/login')
File "build/bdist.linux-x86_64/egg/cork/cork.py", line 209, in login
self._setup_cookie(username)
File "build/bdist.linux-x86_64/egg/cork/cork.py", line 610, in _setup_cookie
session['username'] = username
TypeError: 'NoneType' object does not support item assignment
When I attempt to view the main page, I get this error:
Traceback (most recent call last):
File "/path_to_app/lib/python2.7/bottle-0.11.4-py2.7.egg/bottle.py", line 763, in _handle
return route.call(**args)
File "/path_to_app/lib/python2.7/bottle-0.11.4-py2.7.egg/bottle.py", line 1572, in wrapper
rv = callback(*a, **ka)
File "/path_to_app/cork-example/simple_webapp.py", line 90, in index
aaa.require(fail_redirect='/login')
File "build/bdist.linux-x86_64/egg/cork/cork.py", line 267, in require
cu = self.current_user
File "build/bdist.linux-x86_64/egg/cork/cork.py", line 417, in current_user
username = session.get('username', None)
AttributeError: 'NoneType' object has no attribute 'get'
Is there a newbie mistake I might be making? Or is something else wrong?
I figured it out. It was a newbie mistake. The Bottle documentation says that if you want to use Bottle with mod_wsgi, toward the end of the file, you should use this:
application = default_app()
After getting a better understanding of how this all works, I realized I was sending the wrong application object to mod_wsgi. Instead, I should have used this:
application = app #app was defined earlier in the example application
I have my Flask app which uses Flask-Assets and while trying to run the unittest cases, except the first testcase, others fails with the following RegisterError.
======================================================================
ERROR: test_login_page (tests.test_auth.AuthTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/cnu/env/flenv/lib/python2.7/site-packages/nose/case.py", line 133, in run
self.runTest(result)
File "/Users/cnu/env/flenv/lib/python2.7/site-packages/nose/case.py", line 151, in runTest
test(result)
File "/Users/cnu/env/flenv/lib/python2.7/site-packages/flask_testing.py", line 72, in __call__
self._pre_setup()
File "/Users/cnu/env/flenv/lib/python2.7/site-packages/flask_testing.py", line 80, in _pre_setup
self.app = self.create_app()
File "/Users/cnu/Projects/Bookworm/App/tests/test_auth.py", line 8, in create_app
return create_app('testing.cfg')
File "/Users/cnu/Projects/Bookworm/App/bookworm/__init__.py", line 118, in create_app
configure_extensions(app)
File "/Users/cnu/Projects/Bookworm/App/bookworm/__init__.py", line 106, in configure_extensions
assets.register('js_all', js)
File "/Users/cnu/env/flenv/src/webassets/src/webassets/env.py", line 374, in register
'as "%s": %s' % (name, self._named_bundles[name]))
RegisterError: Another bundle is already registered as "js_all": <Bundle output=assets/packed.js, filters=[<webassets.filter.jsmin.JSMin object at 0x10fa8af90>], contents=('js/app.js',)>
My understanding of why this happens in before the first testcase is run, create_app creates an instance of app and this is maintained for all other testcases.
I tried del(app) in the teardown method, but doesn't help.
Is there some way to fix it?
You probably have a global object for the assets environment, which you have declared as such :
in file app/extensions.py:
from flask.ext.assets import Environment
assets = Environment()
Then, somewhere in your create_app method, you should init the environment:
in file app/__init__.py:
from .extensions import assets
def create_app():
app = Flask(__name__)
...
assets.init_app(app)
...
return app
The thing is that when you initialize your environment with you app, the registered bundles aren't cleared. So you you should do it manually as such in your TestCase:
in file tests/__init__.py
from app import create_app
from app.extensions import assets
class TestCase(Base):
def create_app(self):
assets._named_bundles = {} # Clear the bundle list
return create_app(self)
Hope this helps,
Cheers