首先封裝好mysql類

mysql.php

<?php
class Mysql{
         private static $host="localhost";
         private static $user="root";
         private static $password="123456";
         private static $dbName="test";                     //資料庫名
         private static $charset="utf8";                    //字元編碼
         private static $port="3306";                       //埠號
         private  $conn=null;
         function __construct(){
             $this->conn=new mysqli(self::$host,self::$user,self::$password,self::$dbName,self::$port);
             if(!$this->conn)
             {
                   die("資料庫連線失敗！".$this->conn->connect_error);
             }else{
                 echo "連線成功！";
             }
             $this->conn->query("set names ".self::$charset);
         }
         
         //執行sql語句
         function sql($sql){
             $res=$this->conn->query($sql);
         if(!$res)
              {
                   echo "資料操作失敗";
              }
              else
              {
                   if($this->conn->affected_rows>0)
                   {
                         return $res;
                   }
                   else
                   {
                        echo "0行資料受影響！";
                   }
              }
              
         }
         
         //返回受影響資料行數
         function getResultNum($sql){
	           $res=$this->conn->query($sql);
	           return mysqli_num_rows($res);
           }
         
         //關閉資料庫
         public function close()
         {
             @mysqli_close($this->conn);
         }
}
?>
 

index.php

<?php
require_once "mysql.php";
$conn=new Mysql();
$sql="select * from user";

//執行查詢並獲取查詢結果
$result=$conn->sql($sql);

//輸出受影響資料行數
$num=$conn->getResultNum($sql);
echo "影響的行數：".$num;

//讀取並輸出記錄
while ($row = mysqli_fetch_assoc($result))
{
    echo "{$row['name']} ";
    echo "{$row['password']}";
}

//關閉資料庫
$conn->close();