php简单数据库操作类的封装

<?php   class ConnDB{     private $local;     private $username;     private $pwd;     private $db;     private $connID;     private $code;     public function __construct($local,$username,$pwd,$connID,$code,$db){       $this->local=$local;       $this->username=$username;       $this->pwd=$pwd;       $this->connID=$connID;       $this->code=$code;       $this->db=$db;       $this->connect();     }     public function connect(){       if($this->connID=="pconn"){         $this->connID=mysql_pconnect($this->local,$this->username,$this->pwd)or die("Connect MySQL False");       }else{         $this->connID=mysql_connect($this->local,$this->username,$this->pwd)or die("Connect MySQL False");              }       mysql_select_db($this->db,$this->connID) or die("Connect DB False");       mysql_query("SET NAMES $this->code");       return $this->connID;                 //返回数据库连接对象            }   } class AdminDB{ function executeSQL ($sql, $connID){   $sqlType = strtolower(substr(trim($sql), 0, 6));  //提取SQL语句的类型   $rs = mysql_query($sql,$connID);        //执行SQL语句    if ($sqlType == 'select') {           //如果是select查询     $arrayData = mysql_fetch_array($rs);       //返回查询记录集     if (count($arrayData) == 0 || $rs == false) { //如果没查询到或发生错误       return false;             //返回false     } else {                 //否则         return $arrayData;          //返回记录集     }   } elseif ($sqlType == 'insert' || $sqlType == 'update' || $sqlType == 'delete') { //如果执行插入、更新或删除语句     return $rs;            //返回语句执行状态，即成功返回true，失败返回false   } else {     return false;           //如果不是上述查询，则返回false   } } } $connobj=new ConnDB("localhost","root","root","conn","utf8","db_database20");  //实例化数据库连接类 $conn=$connobj->connect();    //返回连接标识 $admindb=new AdminDB();           //数据库操作类实例化 $res=$admindb->executeSQL ("select * from tb_demo01",$conn); //调用数据库操作类中方法执行查询语句 if($res){          //如果返回结果为真，则输出数据   print_r($res);     //输出一个数组。 } ?>

Array(  [0] => 1  [id] => 1  [1] => php新书上市  [title] => php新书上市  [2] => php新书上市啦，希望大家给出宝贵意见  [content] => php新书上市啦，希望大家给出宝贵意见  [3] => 2010-10-23  [date] => 2010-10-23)