PHP 无法读取sqlserver中的数据，求解

公司原因 必须使用sqlserver  2008R2,

我是用pdo连接数据库代码如下：

<?php

 header('Content-Type:text/html;charset=utf-8');

  try {
     $hostname = "127.0.0.1"; 
     $dbname = "contacts";
     $username = "admin"; 
     $pwd = "admin"; 
     $dsn="sqlsrv:Server=$hostname;database=$dbname";
     
    $conn = new PDO ($dsn,$username,$pwd);
    $conn->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
    echo "mssql database connnection sucessed!";
   } catch (PDOException $e) {
     echo "Failed to get DB handle: " . $e->getMessage() . "\n";
     exit;
   }
$sql="select *from person";
$result=mssql_query($sql);
echo $sql;
?>