使用PDO执行插入/更新查询

Question

我的代码出现问题。我有一个表单，用户填写一些信息并提交它以添加到数据库中。表单可用于提交新行或编辑现有行。但是，这两个查询似乎都没有工作，我看不出原因。任何人都可以在我的代码中看到任何错误吗？

另外，我知道我不应该回应我的PDO异常，但为了调试目的，我暂时这样做了。但没有任何回应。似乎没有任何错误。

try {
    $db = new PDO('mysql:host=x.x.x.x;dbname=xxx', "xxx", "xxx");
} catch (PDOException $ex) {
    echo $ex->getMessage();
}

if (isset($_POST['title'])) {
    try {
        $stmt = $db->prepare("SELECT * FROM xxxxx WHERE Title = :title;");
        $stmt->bindParam(':title', $_POST['title']);
        $stmt->execute();
        $rows = $stmt->fetchAll();
    } catch (PDOException $ex) {
        echo $ex->getMessage();
    }
    if (count($rows) > 0){
    $result = $rows[0];
        if($result['Author'] == $_SESSION['user_name']) {
            try {
                $stmt = $db->prepare("UPDATE xxxxx SET Title = :title, `Short Desc` = :short, Description = :desc, Location = :loc, Genre = :genre, Date = :date, lat = :lat, lng = :lng WHERE ID = :id and Author = :user LIMIT 1;");
                $stmt->bindParam(':title', $_POST['title']);
                $stmt->bindParam(':short', $_POST['shortdesc']);
                $stmt->bindParam(':desc', $_POST['description']);
                $stmt->bindParam(':loc', $_POST['location']);
                $stmt->bindParam(':genre', $_POST['genre']);
                $stmt->bindParam(':date', $_POST['date']);
                $stmt->bindParam(':lat', $_POST['lat']);
                $stmt->bindParam(':lng', $_POST['lng']);
                $stmt->bindParam(':user', $_SESSION['user_name']);
                $stmt->execute();
                $err = "Your ad was successfully updated.";
            } catch (PDOException $ex) {
                echo $ex->getMessage();
            }
        } else {
            $err = "An ad already exists with that title.";
        }
    } else {
        try {
            $stmt = $db->prepare("INSERT INTO xxxxx (`Title`, `Short Desc`, `Description`, `Location`, `Genre`, `Date`, `Author`, `lat`, `lng`) VALUES (:title,:short,:desc,:loc,:genre,:date,:user,:lat,:lng)");
            $stmt->bindParam(':title', $_POST['title']);
            $stmt->bindParam(':short', $_POST['shortdesc']);
            $stmt->bindParam(':desc', $_POST['description']);
            $stmt->bindParam(':loc', $_POST['location']);
            $stmt->bindParam(':genre', $_POST['genre']);
            $stmt->bindParam(':date', $_POST['date']);
            $stmt->bindParam(':lat', $_POST['lat']);
            $stmt->bindParam(':lng', $_POST['lng']);
            $stmt->bindParam(':user', $_SESSION['user_name']);
            $stmt->execute();
            $err = "Your ad was successfully added to our database.";
        } catch (PDOException $ex) {
            echo $ex->getMessage();
        }
    }
}