Qt Remote Database connection

Tonny · 4 Dec 2018, 11:38

How to solve the error QSqlError("2003", "QMYSQL: Unable to connect", "Can't connect to MySQL server on '112.17.98.18' (111)")

When i connecting the remote database it shows the error that given above.But when i connecting the localhost it does not show any error. given below my code.Please help me

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("112.17.98.18"); // fake ip ;
db.setPort(3306);
db.setDatabaseName("root");
db.setUserName("root");
db.setPassword(" ");
db.open();

jsulm · 5 Dec 2018, 05:56

@Tonny said in Qt Remote Database connection:

But when i connecting the localhost it does not show any error

And does it connect then?
Did you try to connect using MySQL client?

koahnig · T Tonny 4 Dec 2018, 11:29

@Tonny

Hi and welcome to devnet forum

Did you check already with a local MySQL db and does it work?

For remote connection you have the classical obstacles like firewall (on both sides) and possibly a virus scanner.
Can you access the database through MySQL workbench without problems or warnings?

dheerendra · 5 Dec 2018, 04:58

@Tonny said in Qt Remote Database connection:

112.17.98.18

Is connectivity to remote server(112.17.98.18) exist ? Can you ping the 112.17.98.18 ? If yes, can you do 'telnet 112.17.98.18 111' from command to check it works. Can you check with some third party tools like DataBase Explorer to connect and query your remote DB ?

SGaist · wrote on 4 Dec 2018, 17:53

Hi,

To add to my fellow, did you also configure your remote database to accept connection from the outside ?

IIRC, accounts like root are only available for local connection.

Tonny · 112.17.98.18

@dheerendra Sir when i type the command telnet it shows the error that 'telnet: Unable to connect to remote host: Connection refused'.I don't know what is the problem.Please help me sir

dheerendra · 5 Dec 2018, 05:43

Are you able to do ping to remote server ping 112.17.98.18 ?

Tonny · wrote on 5 Dec 2018, 05:23

This post is deleted!

Tonny · wrote on 5 Dec 2018, 05:43

@dheerendra ping command is successfully run,But Telnet is not worked

dheerendra · 5 Dec 2018, 06:10

112.17.98.18 is this in LAN ? Hope there is no firewall etc between your box and 112.17.98.18.
Since telnet is not able to connect to port 111 are you sure that SQL is running at the port 111 ?

Tonny · 5 Dec 2018, 08:07

@jsulm mysql client?Please give the procedure to connect it.

Tonny · wrote on 5 Dec 2018, 06:10

@dheerendra
Sir SQL is not running in the port 111.Sql port is 3306 ..

dheerendra · 5 Dec 2018, 06:30

OK can you check telnet 112.17.98.18 3306 ? Does it work ? If it work, atleast DB is up at that port.

Tonny · wrote on 5 Dec 2018, 06:30

@dheerendra sir it shows telnet: Unable to connect to remote host: Connection refused

dheerendra · 6 Dec 2018, 08:15

If you have access to the DB Server box, can you login to the system. In same system can you try to do telnet <IP> Port#. Just check the configuration of the remote sql server. Is it configured to listen for network connections also ?

jsulm · T Tonny 5 Dec 2018, 05:56

@Tonny said in Qt Remote Database connection:

mysql client?Please give the procedure to connect it.

https://dev.mysql.com/doc/refman/8.0/en/mysql.html

Tonny · 6 Dec 2018, 09:02

@dheerendra Sir error solved.
Sir can you please tell me how to sent values through http protocol using qt creator in the REST API
please?Is there any solution for that sir

dheerendra · 6 Dec 2018, 08:45

What was the issue ? Please provide the details here. It helps others. You can move the issue to SOLVED state.

Tonny · wrote on 6 Dec 2018, 08:45

@dheerendra bind address commented. it was 127.0.0.1 (/etc/mysql/mysql.cnf);

dheerendra · wrote on 6 Dec 2018, 08:52

Your server was configured to listen only for local IP address. You tried to connect to server remotely. This was the issue.