此扩展需要 Microsoft ODBC 驱动程序 11 for SQL Server 才能与 SQL Server 通信

ALready在microsoft上下载了sqlsrv...

和我的 phpinfo（）

在 和 上启用php.iniC:\wamp\bin\apache\apache2.4.9\binC:\wamp\bin\php\php5.5.12

并且仍然遇到这样的错误。

Failed to get DB handle: SQLSTATE[IMSSP]: This extension requires the Microsoft ODBC Driver 11 for SQL Server to communicate with SQL Server. Access the following URL to download the ODBC Driver 11 for SQL Server for x86: http://go.microsoft.com/fwlink/?LinkId=163712 

我的代码是

try {
    $dbh = new PDO ("sqlsrv:Server=$host;Database=$db","$user","$pass");
  } catch (PDOException $e) {
    echo "Failed to get DB handle: " . $e->getMessage() . "\n";
    exit;
  }
  $stmt = $dbh->prepare("select top 5 from teams");
  $stmt->execute();
  while ($row = $stmt->fetch()) {
    print_r($row);
  }
  unset($dbh); unset($stmt);