我当前正在使用mysql数据库构建一个机器人，并且试图在heroku上运行它。但是，由于我的主机名是localhost，数据库拒绝连接到数据库。如何使mysql数据库连接到heroku？
更多信息，如果您需要更多信息：
我做了一些研究，发现我需要将mysql数据库主机名更改为0.0.0.0，以使其可以连接到任何地方。但是我不知道应该使用哪个端口。有人可以帮我吗？如何将heroku discord bot连接到数据库并使其运行？这是完整的heroku日志错误。
2020-08-18T13:45:40.371647+00:00 heroku[worker.1]: State changed from starting to up
2020-08-18T13:45:43.831500+00:00 app[worker.1]: Traceback (most recent call last):
2020-08-18T13:45:43.831536+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/sit
e-packages/pymysql/connections.py", line 571, in connect
2020-08-18T13:45:43.831919+00:00 app[worker.1]: **kwargs)
2020-08-18T13:45:43.831924+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/soc
ket.py", line 724, in create_connection
2020-08-18T13:45:43.832413+00:00 app[worker.1]: raise err
2020-08-18T13:45:43.832418+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/soc
ket.py", line 713, in create_connection
2020-08-18T13:45:43.832917+00:00 app[worker.1]: sock.connect(sa)
2020-08-18T13:45:43.832945+00:00 app[worker.1]: ConnectionRefusedError: [Errno 111] Connect
ion refused
2020-08-18T13:45:43.832949+00:00 app[worker.1]:
2020-08-18T13:45:43.832950+00:00 app[worker.1]: During handling of the above exception, ano
ther exception occurred:
2020-08-18T13:45:43.832950+00:00 app[worker.1]:
2020-08-18T13:45:43.832953+00:00 app[worker.1]: Traceback (most recent call last):
2020-08-18T13:45:43.832980+00:00 app[worker.1]: File "sky_rpg.py.py", line 15, in <module>
2020-08-18T13:45:43.833120+00:00 app[worker.1]: cursorclass=pymysql.cursors.DictCursor)
2020-08-18T13:45:43.833124+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/sit
e-packages/pymysql/__init__.py", line 94, in Connect
2020-08-18T13:45:43.833306+00:00 app[worker.1]: return Connection(*args, **kwargs)
2020-08-18T13:45:43.833310+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/sit
e-packages/pymysql/connections.py", line 327, in __init__
2020-08-18T13:45:43.833580+00:00 app[worker.1]: self.connect()
2020-08-18T13:45:43.833585+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.6/sit
e-packages/pymysql/connections.py", line 619, in connect
2020-08-18T13:45:43.833985+00:00 app[worker.1]: raise exc
2020-08-18T13:45:43.834012+00:00 app[worker.1]: pymysql.err.OperationalError: (2003, "Can't
connect to MySQL server on 'localhost' ([Errno 111] Connection refused)")
2020-08-18T13:45:43.963849+00:00 heroku[worker.1]: Process exited with status 1
2020-08-18T13:45:44.028829+00:00 heroku[worker.1]: State changed from up to crashed