Libgda allows data sources (DSN) to be defined and referred to by a unique name which contains all the required information to actually open a connection (except the name and password if they are required); see the Configuration section for more information about how to manage data sources. Of course it's still possible to open a connection without having defined a DSN, in which case a connection string is used to specify all the parameters required to open a connection. For more information about connection strings, see the gda_connection_open_from_string ()'s documentation.

Connections are opened using gda_connection_open_from_dsn () for connections which are defined as a data source (DSN), or or gda_connection_open_from_string () otherwise. Each connection object can then be used to actually execute queries, for example:

void
do_stuff () {
	GdaConnection *connection;
      
        /* open a connection */
	g_print ("CONNECTING\n");
	connection = gda_connection_open_from_dsn ("calvaris", NULL, 
                                                   GDA_CONNECTION_OPTIONS_READ_ONLY, NULL);
	if (!connection) {
		g_print ("CONNECTION FAILED\n");
		return;
	}
	g_print ("CONNECTED\n");
      
        /* use the connection */
	execute_some_queries (connection);
      
        /* close the connection */
        g_object_unref (G_OBJECT (connection));
}
      

Closing the connection can be ordered using gda_connection_close (), or is automatically done when the connection object is destroyed (as is the case in the example above when g_object_unref() is called with the connection as argument).