Question

我正在尝试为我的Apache服务器启动并运行PDO，这样我就可以在与MS SQL数据库交互时使用预准备语句。似乎安装了库并且连接好了，但我无法从表中返回任何信息

   $dbh = new PDO ("dblib:host=$hostname;dbname=$database","$username","$password");
  } catch (PDOException $e) {
    echo "Failed to get DB handle: " . $e->getMessage() . "\n";
    exit;
  }
  $stmt = $dbh->prepare("SELECT * FROM asdf");
  $stmt->execute();
  $result = $stmt->fetchAll(PDO::FETCH_COLUMN, 0);
  print_r($result);  //prints nothing
  var_dump($stmt->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP)); //prints nothing

返回

**array(0) { }**

然而

  $dbh = new PDO("dblib:host=$hostname;dbname=$database", "$username", "$password");
} catch (PDOException $e) {
    echo "Failed to get DB handle: ".$e - > getMessage()."\n";
}
$stmt = $dbh - > prepare("SELECT @@VERSION");
$stmt - > execute();
while ($row = $stmt - > fetch()) {
    print_r($row);
}
unset($dbh);
unset($stmt);

打印出计算机详细信息。

Array ( [] => Microsoft SQL Server 2008 R2 (RTM) - 10.50.1617.0 (X64) Apr 22 2011 19:23:43 Copyright (c) Microsoft Corporation Standard Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1) (Hypervisor) [0] => Microsoft SQL Server 2008 R2 (RTM) - 10.50.1617.0 (X64) Apr 22 2011 19:23:43 Copyright (c) Microsoft Corporation Standard Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1) (Hypervisor) )

所以我认为PDO正在某种程度上发挥作用。我刚刚得到了一些错误的语法吗？

Answer 1

（来自评论中的疑难解答......）

尝试检查$stmt->execute();的返回值以确认查询是否成功。

$stmt->execute();的返回值在成功时为真，所以我会这样做：

$success = $stmt->execute(); 

if(!$success) {
   print_r($stmt->errorInfo()); 
   die("DB Error");
}

MS SQL PDO不会从表中检索数据

1 个答案: