recently I started a small Django project that I developed on a local machine using a SQLite3 database and the integrated development server. I now copied the whole project to a server running Debian.
Everything worked well as long as I kept using the SQLite3 database. Now I wanted to switch to a local MySQL database, so I changed the settings.py file in my project's root folder, created the database and added a user. I then ran syncdb and it created the needed tables without any problems.
Now I wanted to use the app, but I keep getting errors, because Django can not find the tables - neither the 'standard tables' like django_sessions nor my own tables - even though they are there (I checked the database).
The one thing that seems awkward about the DatabaseError pages I get is the following line:
Exception Location: /usr/local/lib/python2.6/dist-packages/django/db/backends/sqlite3/base.py in execute, line 234
It seems like Django is still using the SQLite3 backend even though I set it to use the MySQL backend.
The other thing that nearly makes me freak out is this: I deleted the data.sqlite file in my app's root folder using rm. But when I use my app, the file is being recreated!
Can anyone tell me where I went wrong?
When running in production with mod_wsgi or mod_python, new code isn't incorporated until you reload/restart the webserver.
If you are using apache with mod_wsgi, you can also touch the wsgi.py file to restart the python code only.
If running on apache run "sudo /etc/init.d/apache2 reload" everytime you make a change.
Related
I'm new with python(don't know anything about it), and also in Django... so question is, what and how, step by step, I need to launch existing Django project which I got from github...
so, what I have done already:
installed python
created virtual environment
run python mange.py migrate, but it showed many errors(and I don't know what to do with it and how to fix them), because I can't even connect to DB(previously I worked with MySQL where I can connect by myself and do selects to check something in DB), but now this project uses SQLite3, and I don't know how I can check this database
run python manage.py runserver and I can see my webapp at localhost...
So, main question is, how to properly launch existing Django project?
I'm currently deploying a project to Heroku, however it returns me the following error: ValueError: Related model 'store.user' cannot be resolved.
But there is a way to avoid such error locally. You simply do:
py manage.py migrate store
And then
py manage.py migrate
In other words, if I migrate separetely, I won't face such error. However, Heroku migrates all together, then the deploy fails because of this error.
If I proceed locally as Heroku does, i.e. run
py manage.py migrate
I can effortlessly click on and delete the db.sqlite3 file and makemigrations and migrate separetely. Then the issue would be resolved. However, that's not possible when deploying to Heroku. Thus, how can I delete this file only via terminal? I have been searching, but people only say you click on the file and the delete it, which for me it is not possible.
Thanks
However, Heroku migrates all together, then the deploy fails because of this error
Heroku does nothing of the sort.
Migrations only run on Heroku when you tell them to, either by running something like
heroku run python manage.py migrate
or because you have declared a release process that should run when you deploy a new version, e.g.:
web: gunicorn app.wsgi
release: python manage.py migrate
In both cases you are in charge of what that command is. If you don't want to run python manage.py migrate every time you deploy, remove the release process from your Procfile.
if I migrate separately, I won't face such error
This is concerning.
There could be several causes for this. One common issue is missing dependencies in your migration. If you write a migration in app1 that depends on certain models and tables from app2 existing, you need to add a dependency to the relevant migration in app1, e.g. something like this example from the documentation:
class Migration(migrations.Migration):
dependencies = [
('app1', '0001_initial'),
# added dependency to enable using models from app2 in move_m1
('app2', '0004_foobar'),
]
operations = [
migrations.RunPython(move_m1),
]
If migrations are written properly, such that they accurately reflect the code in each commit, build off each other, have dependencies declared, etc. you should always be able to safely apply them to your database.
Finally, you ask about deleting db.sqlite.
Heroku's filesystem is ephemeral. It gets baked into your application slug at build time, and any changes you make to it get reset every time your dyno restarts. This happens frequently (at least once per day).
This means you can't effectively delete your database file. But it also means you can't save data and expect it to be there when you look it up later! SQLite isn't a good fit for Heroku.
A client-server database like PostgreSQL is a much better choice. Heroku offers its own Postgres service with a free tier.
If you switch, I strongly urge you to switch in development as well. Django's ORM makes it relatively easy to change, but database engines aren't drop-in replacements for each other. I've seen real-world examples where developing on SQLite and deploying to Postgres or MySQL causes things to fail in production that worked in development.
A little background:
I've been working on this project for about six months now and it's been running on Flask the whole time. Everything has been fine, multiple versions of the backend have been deployed live to support an app that's been in production for months now.
The development cycle involves writing everything locally and using Flask-Script's runserver command to test everything locally on localhost:8080 before deploying to a dev server and then finally to the live server.
The Problem: The other day my local flask instance, which runs on localhost:8080 apparently stopped respecting my local files.
I tried adding a new view (with a new template) and I got a 404 error when trying to view it in my browser.
I then tried making some test changes to one of the existing pages by adding a few extra words to the title. I restarted flask and none of those changes appeared.
I then went as far as deleting the entire views.py file. After restarting flask again, much to my dismay, I could still view the pages that were there originally (i.e. before this behavior started).
Finally, I made some changes to the manage.py file, which is where I put all of the Flask-Script commands, and they weren't recognized either. It's as if flask started reading from a cached version of the filesystem that won't update (which very well might be the case but I have no idea why it started doing this or how to fix the issue).
FYI: Browser caching shouldn't be an issue b/c I have the dev tools open with caching disabled. Plus the fact that changes to manage.py aren't being noticed shouldn't have anything to do with the browser.
You've most likely used flask in the DEBUG mode in which it auto reloads templates the app whenever a file changes.
Try using
export FLASK_DEBUG=True
before running
flask run
For more information see http://flask.pocoo.org/docs/1.0/config/#DEBUG
I was having a similar issue and deleting the .pyc files solved it for me.
Hi I am new to Django and have been googling for a whole day without any success.
Basically there is a live/working website built with AngularJS, Django and PostgreSQL (Ubuntu 14.04) and I am trying to download all the files and clone the site into my localhost (Ubuntu 14.04).
After I downloaded the folder and finished install the required packages on my localhost, I run:
python manage.py makemigrations
python manage.py migrate
python manage.py runserver
The server runs without reporting any errors.
However, some of the links are directed to a 404 page, such as this:
http://127.0.0.1:8000/city/chicago
Whereas in the live site, it would direct to the correct working page.
Can someone tell me what may have gone wrong in the process?
Thanks.
Try editing the settings.py file set the DEBUG value to True. Instead of a 404 you should get a full debug of the actual request and see what exactly is missing (I suspect missing data as #NightShadeQueen pointed).
Also you might have a look at django debug toolbar which prints the executed sql queries as well and run them against your local database to see what exactly they return.
I tried to create a sqlalchemy project in pyramid and when I run the server, I get this error,
Pyramid is having a problem using your SQL database. The problem
might be caused by one of the following things:
1. You may need to run the "initialize_MyProject_db" script
to initialize your database tables. Check your virtual
environment's "bin" directory for this script and try to run it.
2. Your database server may not be running. Check that the
database server referred to by the "sqlalchemy.url" setting in
your "development.ini" file is running.
After you fix the problem, please restart the Pyramid application to
try it again.
when I check my development.ini file the sqlite database is configured as this,
sqlalchemy.url = sqlite:///%(here)s/MyProject.sqlite
What needs to changed in here to configure it correctly?
I run on linux box.
You need to create a database in either sqlite,postgres,or any other,Thereafter go to development.ini file edit sqlalchemy.url = sqlite:///%(here)s/MyProject.sqlite and specify the name of your database,then run the initialize_myproject_db development.ini command.if you are using mysql, that line should be
sqlachemy.uri = mysql://username:password#host/dbname
Just trying Pyramid for the first time, I just faced the same problem, after many command combinations, I just got the solution.
Run from the project root, the command:
initialize_tutorial_db development.ini
Info taken from Wiki2 SQLAlchemy tutorial
It says right there in the first point - you need to run initialize_MyProject_db development.ini to create database.
If that's not the case please post the log from running the server.