Problems with second loop and custom SELECT query

  • Colin Helvensteijn

    (@raptornl)


    16 years, 7 months ago

    I’m trying to create a page template that outputs the page content first, and then links to the subpages of that page. I can’t use wp_list_pages() though, because I need to use some custom fields from those subpages.

    So I get those pages with a custom SELECT query directly from the database and create a second loop after the first one, as per these instructions on the Codex.

    The problem is this: inside the second loop, template tags like the_title() and the_permalink() still output their values for the parent page, instead of the subpage the loop is working on at that point. Things like get_post_meta() and the_ID() do contain the right values however.

    Does anyone have any idea why this is, and how I can fix or work around it?

    Or is there perhaps an easier way to to this that I’m not aware of?

    Thanks in advance.

Viewing 6 replies - 1 through 6 (of 6 total)
  • MichaelH

    (@michaelh)

    16 years, 7 months ago

    Take a look at The Loop-Multiple Loops.

    Thread Starter Colin Helvensteijn

    (@raptornl)

    16 years, 7 months ago

    Yeah, read that too. It uses query_posts(). If I could use that, it would indeed probably solve my problem. But I can’t seem to find a page_parent parameter for it.

    Thread Starter Colin Helvensteijn

    (@raptornl)

    16 years, 7 months ago

    Well, after a lot of trying and faling, I finally got it to work. Right underneath the page loop, I make my custom query:

    $parent = 55;
$sql = sprintf(
	'SELECT * FROM  %s
		WHERE post_status = "publish"
		AND post_type = "page"
		AND post_parent = %d
		ORDER BY menu_order',
	$wpdb->posts, $parent
);
$pluginPages = $wpdb->get_results($sql, OBJECT);

    And then create a loop for it:

    if($pluginPages):foreach($pluginPages as $pluginPage):
	setup_postdata($pluginPage);
	$title = get_the_title($pluginPage->ID);
	$permalink = get_permalink($pluginPage->ID);
	// some get_post_meta() calls here

	// make a nice blog-like list of sub pages here

endforeach;endif;

    And the result can be seen here.

    Moderator Samuel Wood (Otto)

    (@otto42)

    WordPress.org Admin

    16 years, 7 months ago

    Instead of doing that, using the get_pages() function might make a bit more sense. It can’t limit based on post_parent, but you can filter by that after retrieving the data.

    The advantage is that the data this way will be cached, instead of making a database hit every single time.

    Thread Starter Colin Helvensteijn

    (@raptornl)

    16 years, 7 months ago

    WordPress does caching by itself? I thought one needed a plugin like WP Cache for that?

    Moderator Samuel Wood (Otto)

    (@otto42)

    WordPress.org Admin

    16 years, 7 months ago

    Yes, WordPress has a built-in object cache. It does memory caching of certain types of things, and can cache object data to disk as well, if you enable it in the wp-config.php file.

Viewing 6 replies - 1 through 6 (of 6 total)
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