Using categories & “stickyness” together

Question

I've got a custom query on my homepage showing all posts in a certain category. I need this query to respect sticky posts, but it seems from my research that category queries ignore stickyness. My question is two (and a half) fold:

1. Can anyone tell me where/how in the database stickyness is applied to a post? I don't see it in wp_postmeta or wp_posts. This one is most important and will probably be enough to get you the win accepted answer.
2. Is there any simple elegant way to grab sticky posts only from a certain category?
3. If not, then how about an ugly way to do it?

Just for the heck of it, here's my query, though I think it won't make a difference to the answer.

$getHighlights = array(
    'posts_per_page' => 7,
    'post_type' => array('post','Event'),
    'category_name' => 'Highlights', 
);

Sorry for the long title, but I wanted to be clear what I was asking for.

Answer 1

Just add 'post__in' => get_option('sticky_posts') to your query, to confine your query to only sticky posts. So,

$getHighlights = array(
    'numberposts' => 7,
    'post_type' => array('post','Event'),
    'post__in' => get_option('sticky_posts'),
    'category_name' => 'Highlights'
);

should work for you.

Edit: This is how you can merge two arrays to get the sticky posts at the top of your query:

$getHighlights_sticky = get_posts( array(
        'numberposts' => 7,
        'post_type' => array('post','Event'),
        'post__in' => get_option('sticky_posts'),//it should be post__in but not posts__in
        'category_name' => 'Highlights'
    ));
$getHighlights_other = get_posts( array(
        'numberposts' => 7 - count( $getHighlights_sticky ),
        'post_type' => array('post','Event'),
        'post__not_in' => get_option('sticky_posts'),//it should be post__not_in but not posts__not_in
        'category_name' => 'Highlights'
    ));
foreach ( array_merge( $getHighlights_sticky, $getHighlights_other ) as $post ) {
    setup_postdata( $post );

    // your display loop

}

This will show 7 posts, with the stickies at the top (of course, this is assuming you don't have more than 7 stickies, otherwise it'll be all messed up...) (edited to use numberposts as per OP's comment below...)

Answer 2

Sticky is not saved per post, there is sticky_posts option that holds array of such. So you can fetch that with $sticky_posts = get_option('sticky_posts');

See Sticky Post Parameters in Codex for details on querying stickies.

I am not entirely sure what would be the best approach to make your query respect stickies. From quick look at code it's likely is_home conditional gets overridden and that kicks stickies off. Might be able to hook somewhere and fake that conditional, but this might break something further in processing.