6.1 Connecting to MySQL

To establish a connection to the MySQL server, retrieve an instance of sql::Connection from a sql::mysql::MySQL_Driver object. A sql::mysql::MySQL_Driver object is returned by sql::mysql::get_mysql_driver_instance().

sql::mysql::MySQL_Driver *driver;
sql::Connection *con;

driver = sql::mysql::get_mysql_driver_instance();
con = driver->connect("tcp://127.0.0.1:3306", "user", "password");

delete con;

Make sure that you free con, the sql::Connection object, as soon as you do not need it any more. But do not explicitly free driver, the connector object. Connector/C++ takes care of freeing that.

Note

get_mysql_driver_instance() calls get_driver_instance(), which is not thread-safe. Either avoid invoking these methods from within multiple threads at once, or surround the calls with a mutex to prevent simultaneous execution in multiple threads.

These methods can be used to check the connection state or reconnect:

• sql::Connection::isValid() checks whether the connection is alive

• sql::Connection::reconnect() reconnects if the connection has gone down

For more information about connection options, see Chapter 10, Connector/C++ Connection Options.