The question says everything. How can I check if my MySQL connection is closed in Python?
I'm using MySQLdb, see http://mysql-python.sourceforge.net/
1 Answer
The Connection.open field will be 1 if the connection is open and 0 otherwise. So you can say
if conn.open:
# do something
4 Comments
Walty Yeung
as a matter of fact, it does not work for me. even if conn.open is true, it would still throw an exception "The server has gone away" when I try to do the query after a long idle time.
Eli Courtwright
@Walty: The
conn.open attribute will tell you whether the connection has been explicitly closed or whether a remote close has been detected. However, it's always possible that you will try to issue a query and suddenly the connection is found to have given out - there is no way to detect this ahead of time (indeed, it might happen during the process of issuing the query), so the only truly safe thing is to wrap your calls in a try/except block.
sadmicrowave
@EliCourtwright - what is the exception type that is thrown if a 'try' fails from a mysql error?
Ben Wheeler
There can be various exception types, but generally you want to catch a MySQLdb.OperationalError , and if the first item in the error when treated as a tuple (e[0], if you're assigning the error to a new variable 'e') == 2006, that indicates that the connection must be re-connected.