php封装的mysqli类完整实例

<?phpheader('content-type:text/html;charset=utf-8');/*掌握满足单例模式的必要条件(1)私有的构造方法-为了防止在类外使用new关键字实例化对象(2)私有的成员属性-为了防止在类外引入这个存放对象的属性(3)私有的克隆方法-为了防止在类外通过clone成生另一个对象(4)公有的静态方法-为了让用户进行实例化对象的操作*/class ConnectMysqli{  //私有的属性  private static $dbcon=false;  private $host;  private $port;  private $user;  private $pass;  private $db;  private $charset;  private $link;  //私有的构造方法  private function __construct($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';    //连接数据库    $this->db_connect();    //选择数据库    $this->db_usedb();    //设置字符集    $this->db_charset();   }   //连接数据库   private function db_connect(){    $this->link=mysqli_connect($this->host.':'.$this->port,$this->user,$this->pass);    if(!$this->link){      echo "数据库连接失败<br>";      echo "错误编码".mysqli_errno($this->link)."<br>";      echo "错误信息".mysqli_error($this->link)."<br>";      exit;    }   }   //设置字符集    private function db_charset(){     mysqli_query($this->link,"set names {$this->charset}");    }    //选择数据库   private function db_usedb(){     mysqli_query($this->link,"use {$this->db}");   }   //私有的克隆   private function __clone(){     die('clone is not allowed');   }   //公用的静态方法   public static function getIntance(){     if(self::$dbcon==false){      self::$dbcon=new self;     }     return self::$dbcon;   }   //执行sql语句的方法    public function query($sql){     $res=mysqli_query($this->link,$sql);     if(!$res){      echo "sql语句执行失败<br>";      echo "错误编码是".mysqli_errno($this->link)."<br>";      echo "错误信息是".mysqli_error($this->link)."<br>";     }     return $res;   }   //打印数据    public function p($arr){      echo "<pre>";      print_r($arr);      echo "</pre>";    }    public function v($arr){    echo "<pre>";      var_dump($arr);      echo "</pre>";    }    //获得最后一条记录id    public function getInsertid(){     return mysqli_insert_id($this->link);    }   /**    * 查询某个字段    * @param    * @return string or int    */    public function getOne($sql){     $query=$this->query($sql);      return mysqli_free_result($query);    }    //获取一行记录,return array 一维数组    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);    }    //获取一条记录,前置条件通过资源获取一条记录    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);    }    //获取多条数据，二维数组    public function getAll($sql){     $query=$this->query($sql);     $list=array();     while ($r=$this->getFormSource($query)) {      $list[]=$r;     }     return $list;    }     /**     * 定义添加数据的方法     * @param string $table 表名     * @param string orarray $data [数据]     * @return int 最新添加的id     */     public function insert($table,$data){     //遍历数组，得到每一个字段和字段的值     $key_str='';     $v_str='';     foreach($data as $key=>$v){      if(empty($v)){       die("error");     }        //$key的值是每一个字段s一个字段所对应的值        $key_str.=$key.',';        $v_str.="'$v',";     }     $key_str=trim($key_str,',');     $v_str=trim($v_str,',');     //判断数据是否为空     $sql="insert into $table ($key_str) values ($v_str)";     $this->query($sql);    //返回上一次增加操做产生ID值     return $this->getInsertid();   }   /*    * 删除一条数据方法    * @param1 $table, $where=array('id'=>'1') 表名 条件    * @return 受影响的行数    */    public function deleteOne($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);      //返回受影响的行数      return mysqli_affected_rows($this->link);    }    /*    * 删除多条数据方法    * @param1 $table, $where 表名 条件    * @return 受影响的行数    */    public function deleteAll($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);      //返回受影响的行数      return mysqli_affected_rows($this->link);    }   /**    * [修改操作description]    * @param [type] $table [表名]    * @param [type] $data [数据]    * @param [type] $where [条件]    * @return [type]    */   public function update($table,$data,$where){     //遍历数组，得到每一个字段和字段的值     $str='';    foreach($data as $key=>$v){     $str.="$key='$v',";    }    $str=rtrim($str,',');    //修改SQL语句    $sql="update $table set $str where $where";    $this->query($sql);    //返回受影响的行数    return mysqli_affected_rows($this->link);   }}?>

//mysqli测试$db=ConnectMysqli::getIntance();//var_dump($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);