How can I connect with my Raspberry Pi to a database on my PC server using wifi?

Question

Connection code:

db = pymysql.connect("192.168.137.1:5901","root","","the-data-base")
cursor=db.cursor()

Result:

Traceback (most recent call last):
  File "adc.py", line 17, in <module>
    db = pymysql.connect("192.168.137.1:5901","root","","the-data-base")
  File "/home/pi/.local/lib/python2.7/site-packages/pymysql/__init__.py", line 90, in Connect
    return Connection(*args, **kwargs)
  File "/home/pi/.local/lib/python2.7/site-packages/pymysql/connections.py", line 699, in __init__
    self.connect()
  File "/home/pi/.local/lib/python2.7/site-packages/pymysql/connections.py", line 967, in connect
    raise exc
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '192.168.137.1:5901' ([Errno -2] Name or service not known)")

Answer 1

How is port specified on "connect()" method? Is it a separate parameter?

Anyway, the usual flow is:

• Can both computers see each other (pinging each other is a good way to know).
• Is the mysql service open for remote connections? If your PC server is a linux box, when you can run this command to know: netstat -lntp. Check for the address associated with port 5901. If it's 127.0.0.1 only then connections to mysql server are only allowed from localhost.
• If it's open to any host, then is there a firewall running on the server that is rejecting this connections? Again, if the server is a linux box, you can check firewall setup with this command: iptables -L -nv.
• If everything looks fine on those fronts, then the next question would be: When you use the application, is there a connection plus associated traffic going on? For this you can use a sniffer on any of the two hosts (wireshark, tshark).

That's a good starting point.