请设计程序，取代以下代码，使数据库能连接成功。MYSQL Bmanager::SqlInit() { MYSQL library; if (0 != mysql_library_init(0, NULL, NULL)) { cout << "mysql数据库初始化失败！" << endl; exit(0); } if (NULL == mysql_init(&library)) { cout << "mysql结构初始化失败！"; exit(0); } mysql_options(&library, MYSQL_SET_CHARSET_NAME, "gb2312");//设置字符集 if (NULL == mysql_real_connect(&library, "localhost", "root", "2b9nq2r7MNY@", "usertab", 3306, NULL, 0)) { cout << "数据库连接失败！" << endl; exit(0); } return library; }

&mysql)) {
cout << "mysql初始化失败！" << endl;
exit(0);
}
if (NULL == mysql_real_connect(&mysql, ""hostname"", ""username"", ""password"", ""dbname"", 0, NULL, 0))
{
cout << "mysql服务器连接失败！" << endl;
exit(0);
}
return mysql;
}

请注意，这并不是最终代码，仅用于参考，可能存在一些逻辑问题。