试用php中oci8扩展

<?php
class Oracle_db{
  public $link;
  public function __construct(){
    $this->link=$this->connect();
    if(!$this->link){
      echo "连接失败";
      exit;
    }
  }
  public function connect(){
    return oci_connect(demo,demo,localhost/xe,AL32UTF8);
  }
  public function execute($sql){
    $result=false;
    $stid=oci_parse($this->link,$sql);
    if($stid){
      $result=oci_execute($stid);
    }
    return array($stid,$result);
  }
  public function fetch_assoc($stid){
    return oci_fetch_assoc($stid);
  }
  
  public function fetch_one($stid){
    $arr=$this->fetch_assoc($stid);
    $this->free($stid);
    return $arr;
  }
  public function fetch_all($stid){
    $arr=array();
    while($row=$this->fetch_assoc($stid)){
      $arr[]=$row;
    }
    $this->free($stid);
    return $arr;
  }
  public function num_rows($stmt){
    return oci_num_rows($stmt);
  }
  public function error(){
    return oci_error($this->link);
  }
  public function free($stid){
    return oci_free_statement($stid); 
  }
  public function server_version(){
    return oci_server_version($this->link);
  }
  public function client_version(){
    return oci_client_version();
  }
  public function __destruct(){
    return oci_close($this->link);
  }
  //
}