MYSQL* mysql = new MYSQL(); //MYSQL mysql;//占用的是栈上的内存 数据库放在线程上，而不是主函数中MYSQL* pDB = mysql_init(mysql); //连接库pDB = mysql_real_connect(pDB, "localhost", "user", "password", "mysql", 3306, NULL, 0); //创建用户sql = "CREATE USER 'hello'@'localhost' IDENTIFIED BY '123456'";mysql_real_query(pDB, sql.c_str(), (unsigned long)sql.size()); //用户提权sql = "GRANT ALL ON *.* TO 'hello'@'localhost'";mysql_real_query(pDB, sql.c_str(), (unsigned long)sql.size()) //用户降权sql = "REVOKE ALL ON *.* FROM 'hello'@'localhost'";mysql_real_query(pDB, sql.c_str(), (unsigned long)sql.size());