php PDO fetchAll 与 foreach 不工作

Question

I'm having some problems with PDO selecting from Database in order to generate dynamic Sitemap file based on articles (essentially pages). PHP is not throwing any errors as I don't see any errors in the error log. Here is the code.

SELECT STATEMENT SNIPPET

$q = $db->prepare("SELECT * FROM articles ORDER BY aid ASC");
$r = $q->fetchAll(PDO::FETCH_ASSOC);

FOR EACH SNIPPET + XML

foreach($r as $row) {

$format_date = date('Y-m-d', $row['date']);
$format_slug = strtolower($row['slug']);

echo '
<url>
    <loc>'.$format_slug.'</loc>
    <lastmod>'.$format_date.'</lastmod>
    <changefreq>monthly</changefreq>
</url>
';

}

XML DATA BEFORE "FOREACH"

echo '<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url>
      <loc></loc>
      <lastmod>2017-01-27</lastmod>
      <changefreq>weekly</changefreq>
      <priority>1.0</priority>
</url>
<url>
      <loc>contact-us</loc>
      <lastmod>2017-01-27</lastmod>
      <changefreq>yearly</changefreq>
</url>
';

XML DATA AFTER "FOREACH"

echo '</urlset>';

And I am using proper PHP header for the XML output at the very top of the page which is

header('Content-Type: text/xml');

So ones I navigate to the Sitemap url, the predefined data in the echo statements is returned, in this case the 2 data snippets in the BEFORE "FOREACH" part and of course the AFTER "FOREACH" is returned.

However for some odd reason no data is being fetched from the database even truth the script seems to work. Am I missing something?

Answer 1

You need to execute the statement.

$q = $db->prepare("SELECT * FROM articles ORDER BY aid ASC");
$q->execute();
$r = $q->fetchAll(PDO::FETCH_ASSOC);

Alternatively you can use PDO::query http://php.net/manual/en/pdo.query.php .

Answer 2

你忘记在statement上调用Execute了吗？