MySql connection threw c++ in ubuntu - mysql

Question

I have installed necessary packages
sudo apt-get install mysql-server
sudo apt-get install libmysqlcppconn-dev
here is my code:
/* Standard C++ includes */
#include <stdlib.h>
#include <iostream>
/*
Include directly the different
headers from cppconn/ and mysql_driver.h + mysql_util.h
(and mysql_connection.h). This will reduce your build time!
*/
#include <mysql_connection.h>
#include <cppconn/driver.h>
#include <cppconn/exception.h>
#include <cppconn/resultset.h>
#include <cppconn/statement.h>
using namespace std;
int main(void)
{
cout << endl;
cout << "Running 'SELECT 'Hello World!' AS _message'..." << endl;
try {
sql::Driver *driver;
sql::Connection *con;
sql::Statement *stmt;
sql::ResultSet *res;
/* Create a connection */
driver = get_driver_instance();
con = driver->connect("tcp://127.0.0.1:11840", "root", "n");
/* Connect to the MySQL test database */
con->setSchema("test");
stmt = con->createStatement();
res = stmt->executeQuery("SELECT 'Hello World!' AS _message"); // replace with your statement
while (res->next()) {
cout << "\t... MySQL replies: ";
/* Access column data by alias or column name */
cout << res->getString("_message") << endl;
cout << "\t... MySQL says it again: ";
/* Access column fata by numeric offset, 1 is the first column */
cout << res->getString(1) << endl;
}``
delete res;
delete stmt;
delete con;
} catch (sql::SQLException &e) {
cout << "# ERR: SQLException in " << __FILE__;
//cout << "(" << __FUNCTION__ << ") on line " »
// << __LINE__ << endl;
cout << "# ERR: " << e.what();
cout << " (MySQL error code: " << e.getErrorCode();
cout << ", SQLState: " << e.getSQLState() << " )" << endl;
}
cout << endl;
return EXIT_SUCCESS;
}
I compiled using:
sudo g++ -Wall -I/usr/include/cppconn -o testapp mysql_connect1.cpp -L/usr/lib -lmysqlcppconn
it got compiled successfully
when I run:
./testapp
Running 'SELECT 'Hello World!' AS _message'...
# ERR: SQLException in mysql_connect1.cpp# ERR:
Can't connect to MySQL server on '127.0.0.1' (111)
(MySQL error code: 2003, SQLState: HY000 )
I get the above error
I made the below changes as suggested here:
run the command vim /etc/mysql/my.cnf
comment bind-address = 127.0.0.1 using the # symbol
restart your mysql server once.
But it still didn't work
output of:
root#knils-HP:/home/knils# sudo netstat -tap | grep mysql
tcp 0 0 *:mysql *:* LISTEN 11840/mysqld
root#knils-HP:/home/knils#
Please can someone help me with this?

Answer 1

Are you sure your server runs on 11840 and the user account you are using is allowed to connect from localhost?
con = driver->connect("tcp://127.0.0.1:11840", "root", "n");
Your console output that more looked like a processID or internal port for me.
MySQL usually runs on 3306 except you changed that on your own.
Can you try:
con = driver->connect("tcp://127.0.0.1:3306", "root", "n");
?