Trouble closing and reopening MySQL connection after catching/handling django.db.utils.OperationalError (2013, Lost connection to server)

问题

I getting a django.db.utils.OpertionalError: (2013, Lost connection to MySQL Server). The reason is because the MAX_TIMEOUT is set to 90 seconds. I'm attempting to catch the error, close the bade connection, and make a fresh query. I would think the following try/except block would catch the error, close the connection and try the same query a second time:

try:
    sku = SkuLight.objects.filter(expansion=card_set).filter(name=card_name)

except OperationalError as e:
    print(e)
    connection.close()
    sku = SkuLight.objects.filter(expansion=card_set).filter(name=card_name)

Am I not closing the connection correctly? If not, how can I close and reopen the connection in the correct way. Thanks.

Here is the full traceback:

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\mysql\base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 250, in execute
    self.errorhandler(self, exc, value)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\connections.py", line 50, in defaulterrorhandler
    raise errorvalue
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 247, in execute
    res = self._query(query)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 411, in _query
    rowcount = self._do_query(q)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 374, in _do_query
    db.query(q)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\connections.py", line 277, in query
    _mysql.connection.query(self, query)
_mysql_exceptions.OperationalError: (2013, 'Lost connection to MySQL server during query')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\site-packages\fbchat\client.py", line 2295, in _parseMessage
    thread_id=thread_id, thread_type=thread_type, ts=ts, metadata=metadata, msg=m)
  File "C:\Users\Jup\Alpha\customer\facebook_listen.py", line 54, in onMessage
    if not sku.exists():
  File "C:\Program Files\Python36\lib\site-packages\django\db\models\query.py", line 715, in exists
    return self.query.has_results(using=self.db)
  File "C:\Program Files\Python36\lib\site-packages\django\db\models\sql\query.py", line 509, in has_results
    return compiler.has_results()
  File "C:\Program Files\Python36\lib\site-packages\django\db\models\sql\compiler.py", line 1032, in has_results
    return bool(self.execute_sql(SINGLE))
  File "C:\Program Files\Python36\lib\site-packages\django\db\models\sql\compiler.py", line 1063, in execute_sql
    cursor.execute(sql, params)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 100, in execute
    return super().execute(sql, params)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Program Files\Python36\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Program Files\Python36\lib\site-packages\django\db\backends\mysql\base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 250, in execute
    self.errorhandler(self, exc, value)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\connections.py", line 50, in defaulterrorhandler
    raise errorvalue
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 247, in execute
    res = self._query(query)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 411, in _query
    rowcount = self._do_query(q)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\cursors.py", line 374, in _do_query
    db.query(q)
  File "C:\Program Files\Python36\lib\site-packages\MySQLdb\connections.py", line 277, in query
    _mysql.connection.query(self, query)
django.db.utils.OperationalError: (2013, 'Lost connection to MySQL server during query')

来源：https://stackoverflow.com/questions/52228881/trouble-closing-and-reopening-mysql-connection-after-catching-handling-django-db