PDO插入查询不起作用[重复]

I'm rebuilding my current script to support PDO instead of MySQL queries. I am stuck on this insert query though, it's not executing and I have no clue why.

Google'd around a bit but couldn't find anything.

                try 
                {
                    $sql = "INSERT INTO
                                news (news_name,
                                    news_description,
                                    news_author,
                                    news_date,
                                    news_link,
                                    news_category)
                            VALUES ('" . trim($_POST['news_name']) . "',
                                '" . trim($_POST['news_description']) . "',
                                " . $_SESSION['admin_id'] . ",
                                NOW(),
                                '" . trim($_POST['news_link']) . "',
                                '" . trim($_POST['news_category']) . "'
                                )";
                    $results = $db->exec($sql);
                    $id = $db->lastInsertId();

                    if($results)
                    {
                        echo $id;
                        echo '<p>News item added succesfully</p>';
                        echo '<a href="admin.php">Click here to return to the admin panel</a>';                     
                    }
                } 
                catch(PDOException $e)
                {
                    echo $e->getMessage();
                }
            } 
            ?>

</div>

First, set PDO to throw exceptions when it encounters an error if you haven't already...

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

Now, prepare an INSERT statement with parameters

$sql = <<<_SQL
INSERT INTO `news` (news_name, news_description, news_author,
                    news_date, news_link, news_category)
VALUES (:name, :description, :author_id, NOW(), :link, :category)
_SQL;
$stmt = $db->prepare($sql);

Then execute it with your values

$stmt->execute([ // PHP 5.4 short array syntax, use array(...) if not available
    ':name'        => trim($_POST['news_name']),
    ':description' => trim($_POST['news_description']),
    ':author_id'   => $_SESSION['admin_id'],
    ':link'        => trim($_POST['news_link']),
    ':category'    => trim($_POST['news_category'])
]);

And finally...

catch(PDOException $e)
{
    echo $e->getMessage();        
}

Never do this. Not only does it expose internal information to end users but it lets your program continue on as if nothing happened.

When developing, let the exception go unhandled, thus terminating execution. In production, implement a high-level exception handler that can log and / or notify you of the problem while presenting users with a friendly error message.