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Python

Posted by Sean Manners
Sean Manners
14,816 Points

Database Locked

So, I've been stuck on the Flask Track since every time I attempt to follow along (Started back at the Macros video), I end up with a 'Database Locked' error.

Fixing it initially only took deleting the database and re-running the code. Now however, the issue persists as soon as the database is recreated for the newly attempted version.

It will work for roughly 30 seconds, and then I'll get a Jinja update saying 'peewee.OperationalError: database is locked' . I've tried a few different things, but I can't quite figure out what's causing it overall. Any insight, would be greatly appreciated.

I've taken a snapshot of the workspace here, if that helps. https://w.trhou.se/v6szgtduv7

Thank you!

Edit: I've also perused the community related to previous issues of similar nature, but I can't quite seem to find the resolution, day three of this particular issue.

2 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,468 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,468 Points

Based on this Community post, the process of creating the database can be interrupted by the OS which may cause the database lock to get corrupted. It's better to wrap the code using a DATABASE.transastion():

if __name__ == '__main__':
    models.initialize()
    try:
        with models.DATABASE.transaction():  # added this wrapper
            models.User.create_user(
                username='kennethlove',
                email='kenneth@teamtreehouse.com',
                password='password',
                admin=True
        )
    except ValueError:
        pass
    app.run(debug=DEBUG, host=HOST, port=PORT)
Sean Manners
Sean Manners
14,816 Points

Thanks Chris, this did it. I suppose I overlooked that post, my apologies!

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

Try typing rm social.db into the Console (make sure you are not in the Python shell or in the middle of running the Flask app). It should delete the file :smile:

Sometimes deleting files in the File Tree doesn't work.

~Alex

Sean Manners
Sean Manners
14,816 Points

Thanks Alex - I did give that a go, and it appeared to work for roughly the same duration - about 30 seconds. The error seems to be occurring when I try to use any sort of functionality on the preview (Registering, sign in, etc.), as whenever I submit/post, it returns with the database being locked.

Alexander Davison
Alexander Davison
65,469 Points

Ouch... Tagging Kenneth Love & Chris Freeman