<?phpheader('content-type:text/html;charset=utf-8');/*掌握滿足單例模式的必要條件(1)私有的構(gòu)造方法-為了防止在類外使用new關(guān)鍵字實(shí)例化對(duì)象(2)私有的成員屬性-為了防止在類外引入這個(gè)存放對(duì)象的屬性(3)私有的克隆方法-為了防止在類外通過clone成生另一個(gè)對(duì)象(4)公有的靜態(tài)方法-為了讓用戶進(jìn)行實(shí)例化對(duì)象的操作*/class ConnectMysqli{  //私有的屬性  private static $dbcon=false;  private $host;  private $port;  private $user;  private $pass;  private $db;  private $charset;  private $link;  //私有的構(gòu)造方法  private function __construct($config=array()){    $this->host = $config['host'] ? $config['host'] : 'localhost';    $this->port = $config['port'] ? $config['port'] : '3306';    $this->user = $config['user'] ? $config['user'] : 'root';    $this->pass = $config['pass'] ? $config['pass'] : 'root';    $this->db = $config['db'] ? $config['db'] : 'small2';    $this->charset=isset($arr['charset']) ? $arr['charset'] : 'utf8';    //連接數(shù)據(jù)庫    $this->db_connect();    //選擇數(shù)據(jù)庫    $this->db_usedb();    //設(shè)置字符集    $this->db_charset();   }   //連接數(shù)據(jù)庫   private function db_connect(){    $this->link=mysqli_connect($this->host.':'.$this->port,$this->user,$this->pass);    if(!$this->link){      echo "數(shù)據(jù)庫連接失敗<br>";      echo "錯(cuò)誤編碼".mysqli_errno($this->link)."<br>";      echo "錯(cuò)誤信息".mysqli_error($this->link)."<br>";      exit;    }   }   //設(shè)置字符集    private function db_charset(){     mysqli_query($this->link,"set names {$this->charset}");    }    //選擇數(shù)據(jù)庫   private function db_usedb(){     mysqli_query($this->link,"use {$this->db}");   }   //私有的克隆   private function __clone(){     die('clone is not allowed');   }   //公用的靜態(tài)方法   public static function getIntance(){     if(self::$dbcon==false){      self::$dbcon=new self;     }     return self::$dbcon;   }   //執(zhí)行sql語句的方法    public function query($sql){     $res=mysqli_query($this->link,$sql);     if(!$res){      echo "sql語句執(zhí)行失敗<br>";      echo "錯(cuò)誤編碼是".mysqli_errno($this->link)."<br>";      echo "錯(cuò)誤信息是".mysqli_error($this->link)."<br>";     }     return $res;   }   //打印數(shù)據(jù)    public function p($arr){      echo "<pre>";      print_r($arr);      echo "</pre>";    }    public function v($arr){    echo "<pre>";      var_dump($arr);      echo "</pre>";    }    //獲得最后一條記錄id    public function getInsertid(){     return mysqli_insert_id($this->link);    }   /**    * 查詢某個(gè)字段    * @param    * @return string or int    */    public function getOne($sql){     $query=$this->query($sql);      return mysqli_free_result($query);    }    //獲取一行記錄,return array 一維數(shù)組    public function getRow($sql,$type="assoc"){     $query=$this->query($sql);     if(!in_array($type,array("assoc",'array',"row"))){       die("mysqli_query error");     }     $funcname="mysqli_fetch_".$type;     return $funcname($query);    }    //獲取一條記錄,前置條件通過資源獲取一條記錄    public function getFormSource($query,$type="assoc"){    if(!in_array($type,array("assoc","array","row")))    {      die("mysqli_query error");    }    $funcname="mysqli_fetch_".$type;    return $funcname($query);    }    //獲取多條數(shù)據(jù)，二維數(shù)組    public function getAll($sql){     $query=$this->query($sql);     $list=array();     while ($r=$this->getFormSource($query)) {      $list[]=$r;     }     return $list;    }     /**     * 定義添加數(shù)據(jù)的方法     * @param string $table 表名     * @param string orarray $data [數(shù)據(jù)]     * @return int 最新添加的id     */     public function insert($table,$data){     //遍歷數(shù)組，得到每一個(gè)字段和字段的值     $key_str='';     $v_str='';     foreach($data as $key=>$v){      if(empty($v)){       die("error");     }        //$key的值是每一個(gè)字段s一個(gè)字段所對(duì)應(yīng)的值        $key_str.=$key.',';        $v_str.="'$v',";     }     $key_str=trim($key_str,',');     $v_str=trim($v_str,',');     //判斷數(shù)據(jù)是否為空     $sql="insert into $table ($key_str) values ($v_str)";     $this->query($sql);    //返回上一次增加操做產(chǎn)生ID值     return $this->getInsertid();   }   /*    * 刪除一條數(shù)據(jù)方法    * @param1 $table, $where=array('id'=>'1') 表名 條件    * @return 受影響的行數(shù)    */    public function deleteOne($table, $where){      if(is_array($where)){        foreach ($where as $key => $val) {          $condition = $key.'='.$val;        }      } else {        $condition = $where;      }      $sql = "delete from $table where $condition";      $this->query($sql);      //返回受影響的行數(shù)      return mysqli_affected_rows($this->link);    }    /*    * 刪除多條數(shù)據(jù)方法    * @param1 $table, $where 表名 條件    * @return 受影響的行數(shù)    */    public function deleteAll($table, $where){      if(is_array($where)){        foreach ($where as $key => $val) {          if(is_array($val)){            $condition = $key.' in ('.implode(',', $val) .')';          } else {            $condition = $key. '=' .$val;          }        }      } else {        $condition = $where;      }      $sql = "delete from $table where $condition";      $this->query($sql);      //返回受影響的行數(shù)      return mysqli_affected_rows($this->link);    }   /**    * [修改操作description]    * @param [type] $table [表名]    * @param [type] $data [數(shù)據(jù)]    * @param [type] $where [條件]    * @return [type]    */   public function update($table,$data,$where){     //遍歷數(shù)組，得到每一個(gè)字段和字段的值     $str='';    foreach($data as $key=>$v){     $str.="$key='$v',";    }    $str=rtrim($str,',');    //修改SQL語句    $sql="update $table set $str where $where";    $this->query($sql);    //返回受影響的行數(shù)    return mysqli_affected_rows($this->link);   }}?>

//mysqli測(cè)試$db=ConnectMysqli::getIntance();//var_dump($db);/*$sql="select * from acticle";$list=$db->getAll($sql);$db->p($list);*//*$sql="select * from acticle where acticle_id=95";$list=$db->getRow($sql);$db->p($list);*//*$sql="select title from acticle";$list=$db->getOne($sql);$db->p($list);不行*///$list=$db->insert("users",$_POST);//$del=$db->deleteOne("users","id=29");//$del=$db->deleteAll("users","id in(27,28)");//$up=$db->update("users",$_POST,"id=27");//print_R($list);