Sqlite3, OperationalError: unable to open database

Question

Question: Why can't I open the database?

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Info: I'm working on a project using sqlite3 database. I wrote a test program that runs and passes it the database:

/tmp/cer/could.db

The unit test program can make the db without any problem. But, when I actually use the program passing the same location to it, i got below error:

OperationalError: unable to open database file

I've tried doing it with:

1) an empty database.
2) the database and the unit test left behind.
3) no database at all.

In three cases, I got the above error. The most frustrating part has to be the fact that the unittest can do it just fine, but the actual program can't.

Any clues as to what on earth is going on?

Answer 1

On unix I got that error when using the ~ shortcut for the user directory. Changing it to /home/user resolved the error.

Answer 2

This is definitely a permissions issue. If someone is getting this error on linux, make sure you're running the command with sudo as the file most likely is owned by root. Hope that helps!

Answer 3

In my case, the solution was to use an absolute path, to find an existing file:

import os.path
filepath = os.path.abspath(filepath)
# Leave this out if the file doesn't exist yet
assert os.path.exists(filepath), "The file doesn't exist"
conn = sqlite3.connect(filepath)

I don't know why this fix works: the path only contained ASCII characters and no spaces. Still it made the difference.

For reference: Windows 7, Python 3.6.5 (64-bit).

I was not able to reproduce the issue on another machine (also Windows 7, Python 3.6.4 64-bit), so I have no idea why this fix works.

Answer 4

This worked for me:

conn = sqlite3.connect("C:\\users\\guest\\desktop\\example.db")

Note: Double slashes in the full path

Using python v2.7 on Win 7 enterprise and Win Xp Pro

Hope this helps someone.

Answer 5

Use the fully classified name of database file

Use- /home/ankit/Desktop/DS/Week-7-MachineLearning/Week-7-MachineLearning/soccer/database.sqlite

instead-

Answer 6

For any one who has a problem with airflow linked to this issue.

In my case, I've initialized airflow in /root/airflow and run its scheduler as root. I used the run_as_user parameter to impersonate the web user while running task instances. However airflow was always failing to trigger my DAG with the following errors in logs:

sqlite3.OperationalError: unable to open database file
...
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file

I also found once I triggered a DAG manually, a new airflow resource directory was automatically created under /home/web. I'm not clear about this behavior, but I make it work by removing the entire airflow resources from /root, reinitializing airflow database under /home/web and running the scheduler as web under:

[root@host ~]# rm -rf airflow
[web@host ~]$ airflow initdb
[web@host ~]$ airflow scheduler -D

If you want to try this approach, I may need to backup your data before doing anything.