PHP+Smarty：高效实现用户信息的增删改查操作

<?php
class UserInfo{
 private $userName;  //属性,用户名
 private $userPSW ;  //属性,用户密码
 private $userAge ;  //属性,用户年龄
 private $userGrade ; //属性,用户级别
 private $userInfo; //存储数据库返回信息的数组变量.

 public function __construct($name){
  require_once("db_config.php"); //包含配置信息.
  $sql = "select * from e_user where username='$name' "; //书写sql
  $conn  = mysql_pconnect($db_server, $db_user, $db_pwd);//建立mysql连接
  $my_db = mysql_select_db($db_name,$conn);//选择数据库
  $result = mysql_query($sql, $conn); // 执行查询语句
  $this->userInfo = mysql_fetch_array($result); //返回查询结果到数组
  mysql_close($conn); //关闭数据库连接
  $this->getInfo(); //调用传递信息的方法.
 }
 // 获取信息传递给属性的方法
 private function getInfo(){
  $this->userName = $this->userInfo["username"];
  $this->userPSW = $this->userInfo["userpsw"];
  $this->userAge = $this->userInfo["userage"];
  $this->userGrade = $this->userInfo["usergrade"];
 }
 
 //返回每个属性的public 方法.
 public function getUserName(){
  return $this->userName;
 }