python - pyMySQL:如何检查连接是否已经打开或关闭

Question

我收到错误 InterfaceError (0, '')。 Pymysql 库中有没有办法我可以检查连接或游标是否关闭。对于游标，我已经在使用这样的上下文管理器:

with db_connection.cursor() as cursor:
  ....

Answer 1

您可以使用 Connection.open 属性。

如果连接打开，Connection.open 字段将为 1，否则为 0。所以你可以说

if conn.open:
    # do something

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