PHP代码如果想要用以上的方式兼容linux服务器和windows服务器，那么大概的示例代码是这样的。

<?php

header("Content-type: text/html; charset=utf-8");

if(PATH_SEPARATOR==':')

    echo '本机操作系统是：Linux<br>';

else

    echo '本机操作系统是：Windows<br>';

  try {

      //服务器

      $host = "127.0.0.1";

      $port = '1433';

      $dbname = "databasename";

      $username = "sa";

      $pw = "xxxwtxxx";

      $dbh = null;

      if(PATH_SEPARATOR==':'){

          $dbh = new PDO ("dblib:host=$host:$port;dbname=$dbname","$username","$pw");

      }else{

          $dbh = new PDO("sqlsrv:Server=$host,$port;Database=$dbname",$username,$pw);

      }

  } catch (PDOException $e) {

      echo "Failed to get DB handle: " . $e->getMessage() . "\n";

      exit;

  }

  $stmt = $dbh->prepare("SELECT top 1 * FROM tablename");

  $stmt->execute();

  while ($row = $stmt->fetch()) {

      var_dump($row);

  }

  unset($dbh); unset($stmt);