peewee.OperationalError：由于未完成的语句或未完成的备份而无法关闭

Question

I want to write a script in python which will work in loop. Script uses sqlite database which is referenced by peewee. I can't put all code in here because it has a few hundreds of lines, but I'll show the part of my code written in peewee. When I run my code only once then everything works fine, although it must work for a few days, so it has to be running in loop. When I do the loop then I get this error in the second iteration:

peewee.OperationalError: Connection already opened.

I tried to solve it by simply closing connection using this line: db.close()

But... then I get this:

File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2677, in 
  close
       self._close(self._state.conn)
 File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2683, in _ 

close conn.close() sqlite3.OperationalError: unable to close due to unfinalized statements or unfinished backups

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "run.py", line 76, in <module>
    main()
  File "run.py", line 69, in main
    db.close()
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2677, in 
close
    self._close(self._state.conn)
 File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2509, in 
__exit__
    reraise(new_type, new_type(*exc_args), traceback)
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 186, in 
reraise
    raise value.with_traceback(tb)
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2677, in 
close
    self._close(self._state.conn)
  File "/usr/local/lib/python3.6/site-packages/peewee.py", line 2683, in 
 _close
    conn.close()
peewee.OperationalError: unable to close due to unfinalized statements or 
unfinished backups

class PeeweeDatabase:

def __init__(self):
    db.connect()

@staticmethod
def create_tables():
    with db:
        db.create_tables([Model1, Model2, Model3])

@staticmethod
def save_Problem(view_name, id, link):
    current_table = globals()[view_name]

    try:
        current_table.insert({
            NewProblemCreated.ID: id,
            NewProblemCreated.link: link,
            NewProblemCreated.deliveryDate: 0,
            NewProblemCreated.firstEncounter: datetime.now(),
            NewProblemCreated.latestEncounter: datetime.now(),
            NewProblemCreated.HowMuchTimesSent: 0,
            NewProblemCreated.EncounteredBefore: False,
        }).execute()
        logger.info('Problem {} saved'.format(id))
    except IntegrityError:
        pass

@staticmethod
def update_latest_delivery(view_name, id):
    current_table = globals()[view_name]

    (current_table
        .update(deliveryDate=datetime.now(), HowMuchTimesSent=current_table.HowMuchTimesSent+1)
        .where(current_table.ID == pr_id)
        .execute())

@staticmethod
def check_last_delivery(view_name, pr_id):
    current_table = globals()[view_name]

    res = (current_table
           .select(current_table.deliveryDate)
           .where(pr_id == current_table.prID)
           .namedtuples()
           )
    return res[0][0]

Anyone faced this problem before?

Earlier I used SQL queries directly and had no problems but I wanted to use some ORM.

Answer 1

My guess is you're using an ancient version of SQLite on your system. The python sqlite3 driver will use sqlite3_close_v2 if SQLite is > 3.07, otherwise it uses sqlite3_close , which is responsible for this issue.

You can try exhausting any cursors and rolling-back any potentially open transactions. You can also run in autocommit mode.

Answer 2

Well, I know already how to fix this... I have deleted db.connect and now everything works fine. I thought that I have tried this already but it seems I didn't. I guess when im using ORM I should avoid to using sql commands and let ORM do it on it's own way.