PDO准备的SELECT语句不起作用 [英] PDO prepared SELECT statement isn't working

问题描述

我很难使用PDO准备好的语句从表中检索数据，

i'm having a hard time trying to retrieve data from a table using PDO prepared statements,

下面是我的代码不起作用，$ post始终为空.

Below is my code which isn't working, $post is always empty.

    //connection to db has been made
    $stmt = $db->prepare("SELECT * FROM posts WHERE id = ?");
    $stmt->bindValue(1,$_GET['id']);
    $post = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->execute();

我非常有信心问题会出现在第三行中，所以请让我知道是否还有另一种获取数据的方法，而不是fetchAll(PDO :: FETCH_ASSOC).

I'm quite confident the problem occurs in the third line, so please let me know if there is another way to get the data rather than fetchAll(PDO::FETCH_ASSOC).

非常感谢.

推荐答案

您实际上并没有执行该方法，但否则，您的代码看起来还不错！

You're not actually executing the method, but otherwise, your code looks fine!

// Assuming $_GET['id'] has a value (thanks Mike!)
$stmt = $db->prepare("SELECT * FROM posts WHERE id = ?");
$stmt->bindValue(1, $_GET['id']);
$stmt->execute();

$post = $stmt->fetchAll(PDO::FETCH_ASSOC);

顺便说一句，我还要确保$_GET['id']是有效的； is_int($_GET['id'])返回可以提供帮助的布尔值.

As an aside, I'd also make sure that $_GET['id'] is valid; is_int($_GET['id']) returns a boolean that could help.

获取帖子后，请确保对其进行迭代.

After fetching your posts, make sure to iterate through them.

if($post != null && count($post) > 0) {
    for($i = 0; $i < count($post); $i++) {
        echo $post[$i]['title'] . '<br />';
    }
}

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