php封装的mysqli类完整实例

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);
/*
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[&#39;host&#39;] ? $config[&#39;host&#39;] : &#39;localhost&#39;;
    $this->port = $config[&#39;port&#39;] ? $config[&#39;port&#39;] : &#39;3306&#39;;
    $this->user = $config[&#39;user&#39;] ? $config[&#39;user&#39;] : &#39;root&#39;;
    $this->pass = $config[&#39;pass&#39;] ? $config[&#39;pass&#39;] : &#39;root&#39;;
    $this->db = $config[&#39;db&#39;] ? $config[&#39;db&#39;] : &#39;small2&#39;;
    $this->charset=isset($arr[&#39;charset&#39;]) ? $arr[&#39;charset&#39;] : &#39;utf8&#39;;
    //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.&#39;:&#39;.$this->port,$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(&#39;clone is not allowed&#39;);
   }
   //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 class="brush:php;toolbar:false">";
      print_r($arr);
      echo "

"; } public function v($arr){ echo "

";
      var_dump($arr);
      echo "

"; } //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);