PHP实现的数据库封装类

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PHP实现的数据库封装类

作者：用户投稿来源：网络发布时间： 12/12/10

PHP学习实例，数据库封装类。

<?php
class Core{
/*对数组进行继承*/
static function inHerit($arr_orgin,$arr_output){
return array_merge($arr_orgin,$arr_output);

}

/*打印错误*/
static function throwError($errmsg){
    echo ''<p>error:''.$errmsg.''</p>'';
    exit();
}
}
?>
<?php
class db{
    private $result = array();
    private $connector = array();
    private $configs = array();
    private $active = 0;
    private $default_config = array(
        ''dbtype'' => ''MySQL'',
          ''index'' => 0,''user'' => ''root'', ''pwd'' => '''' ,''host'' => ''localhost'' ,''port''=> 3306,''charset'' => ''utf8'' ,''dbname'' => null
    );

   /*初始化*/
   public function __construct($config = array()){
     if($config) $this->connect($config);
   }

   public function __destruct(){
       foreach($this->connector as $index => $connect)
           $this->{''_''.$this->configs[$index][''dbtype''].''_close''}($connect);

   }

   private function _mysql_close($connect){
      mysqli_close($connect);
   }
   /*选择连接*/
   public function selectConnect($index){
        return isset($this->connector[$index]) && (($this->active = $index) || true);
   }
   /*建立连接*/
   public function connect($config){
     (!isset($config[''index''])) && $config[''index''] = $this->default_config[''index'']++ ;

     $config = Core::inHerit($this->default_config,$config);
     !in_array($config[''dbtype''],array(''mysql'')) && Core::throwError(''未支持的数据库类型'');
     extract($config);
     $this->configs[$index] = $config;
     $this->{''_''.$config[''dbtype''].''_connect''}($user, $pwd,$host,$dbname,$charset,$index,$port);

   }
   private function _mysql_connect($user = ''root'', $pwd = '''' ,$host = ''localhost'' ,$dbname = null,$charset = ''utf8'' ,$index = 0 ,$port = 3306){
     $this->connector[$index] = mysqli_connect ( $host, $user, $pwd , null, $port) or Core::throwError(mysql_error());
     $this->active = $index;
     if($dbname) $this->selectDb($dbname,$charset);
   }

   /*取得当前连接*/
   private function _getConnect(){
     return $this->connector[$this->active];
   }
   /*取得当前连接使用的数据库类型带参数自动拼接为函数名*/
   private function _getDbTypeFunc($funcname = null){
     $dbtype = $this->configs[$this->active][''dbtype''];
     return $funcname?''_''.$dbtype.''_''.$funcname:$dbtype;
   }
   /*选择数据库*/
   public function selectDb($dbname,$charset){
     mysqli_select_db($this->_getConnect(),$dbname) or Core::throwError(mysql_error());
     $this->_mysql_query(''set names ''.$charset);
   }

   /*执行语句*/
   private function _mysql_query($sql){
    $result = mysqli_query($this->_getConnect(),$sql) or Core::throwError(mysql_error());
    return $result;
   }

   private function _mysql_bind_by_name($sql , $sqlv){
        $sql_param = array();

        $getparam = $getparam2 =   ''\w+?'';// $getparam = array_keys($sqlv); implode(''|'',$getparam);
        preg_match_all(''/:(''.$getparam.'')\b/iU'',$sql,$getparam) or   Core::throwError(''参数绑定错误'');

        $getparam = $getparam[1];
        $getparam = array_flip($getparam);

count($getparam) != count($sqlv) || array_diff_key($getparam,$sqlv) && Core::throwError(''参数不匹配'');

        $sql = preg_replace(''/:(''.$getparam2.'')\b/iU'',''?'',$sql) ;

        $sqlv = array_merge($getparam,$sqlv);

        unset($getparam2);
        unset($getparam);


        $stmt = mysqli_prepare($this->_getConnect(),$sql) or Core::throwError(''wrong sql:''.$sql);


        $ptype = '''';
        $bindparam = array($stmt,'''');

        foreach ($sqlv as $k => $v){
            $ptype .= $this->_getParamType($k);
            $bindparam[] = $v;
            }
        $bindparam[1] = $ptype;

        call_user_func_array(''mysqli_stmt_bind_param'',$bindparam);
        return $this->_mysql_stmt_exec($stmt,$sql);
   }

   private function _mysql_bind_in_sort(){
       $argus = func_get_args() ;
       $sql = array_shift($argus);
       $stmt = mysqli_prepare($this->_getConnect(),$sql) or Core::throwError(''wrong sql:''.$sql);
       $pcount = mysqli_stmt_param_count($stmt);

       $pcount != count($argus) && Core::throwError(''参数不匹配'');
       $ptype = str_repeat(''s'',$pcount);
       array_splice($argus, 0, 0 ,array($stmt,$ptype));
       call_user_func_array(''mysqli_stmt_bind_param'',$argus);

return $this->_mysql_stmt_exec($stmt,$sql);
}

private function _mysql_stmt_exec($stmt,$sql){
mysqli_stmt_execute($stmt);

        if($this->isSelect($sql)){ ///返回值绑定

            mysqli_stmt_bind_result($stmt,$a);
             while ($stmt->fetch()) {
                    print_r($a);
                    echo ''<br/>'';
                }
         }
         $stmt->close();

   }

   /*根据参数形式使用不同函数*/
   private function _mysql_iquery($sql , $sqlv = array()){
     if ($sqlv){
         if (is_array($sqlv))
             return $this->_mysql_bind_by_name($sql , $sqlv);
         else{
             $argus = func_get_args() ;
             return call_user_func_array(array($this,''_mysql_bind_in_sort''),$argus);
         }
     }else{
         return $this->_mysql_query($sql,$sqlv);
     }
   }

/*根据键名前缀区分数据类型*/
private function _getParamType($key){
     $r = ''s'';
     /*首字母小写第二个字母大写则第一个字母为模式前缀*/
     $mode = array(
       ''i'' => ''i'',''s'' => ''s'',''d'' => ''d'',''b'' => ''b''
     );
     if (strlen($key) >= 2 && $key[0] == strtolower($key[0]) && $key[1] == strtoupper($key[1]) && in_array($key[0],$mode))
        $r = $mode[$key[0]];

     return $r;
}
/*分析sql语句判断行为*/
private function _cmdType($sql){
      return substr(strtolower($sql),0,strpos($sql,'' ''));

   }
   /*分析sql语句是否为select语句*/
   private function isSelect($sql){
        return ''select'' == $this->_cmdType($sql);
   }
   public function query($sql , $sqlv = array()){
       $func = $this->_getDbTypeFunc(''iquery'');

       $argus = func_get_args() ;
       $argus[0] = trim($argus[0]);
       return call_user_func_array(array($this,$func),$argus);
   }

}
?>