PHP でデータベースを変更するにはいくつかの方法があります

 <?php
  $con=mysql_connect("localhost" ,"root","password")
  if($con){
    mysql_select_db("db_name",$con);
    $sql="select * from table_name where id=1";
    $result=mysql_query($sql);
    while($row=mysql_fetch_row($result)){
        echo  "$row";
    }
  }else{
    die("无法连接数据库".mysql_error());
  }
  mysql_close($con);
  ?>

<?php
    $con=new mysqli("localhost","root","password","db_name");
    if(!mysqli_connect_error()){
        $sql="select * from table_name where id=1";
        $result=$con->query($sql);
    while($row=$result->fetch_row($result)){
        echo  "$row";
    }
      }else{
        die("无法连接数据库".mysql_error());
      }

 <?php
        $pdo=new      
        PDO(&#39;mysql:host=localhost;dbname=db_name&#39;,"root",
        $sql="select * from table_name where id=1";
       "password");
        try{
              $result=$pdo->query($sql);
              foreach($result as $k){
                    print_r($k);
              }
            }catch(PDOException $e){
                       echo $e->getMessage();
            }
    ?>

require_once './adodb5/adodb.inc.php';
  $conn = &ADONewConnection('mysql');
  $conn->connect('localhost','root','','test');
  $conn->Execute("set names utf8");
  $res = $conn->Execute("select * from user");
  if (!$res){
     echo $conn->ErrorMsg();
  }else{
     var_dump($res);
   }