pull all posts' meta key values from current category only

Question

I am having trouble figuring out how to pull the meta key values for just one category. I can pull all the meta key values (for meta_key "city") in all categories no problem like this:

 $querystr = "SELECT $wpdb->posts.*,$wpdb->postmeta.* 
    FROM $wpdb->posts, $wpdb->postmeta
    WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id AND meta_key = 'city'";

but cannot figure out a way to limit it to a single category. Every time I try to modify the query above with various left and inner and right joins, I get back nothing useful.

Any ideas? Ideally it would filter by the category page we are on, but If I need to create individual category pages, I can deal with that...

Answer 1

Instead of formulating your own query, why not use WP_Query?

WP_Query( array('cat' => yourcatid, 'meta_key' => 'city') );

This would pull all the keys of City out for a given category id

http://codex.wordpress.org/Class_Reference/WP_Query

Answer 2

Apologies, but my PHP isn't wonderful... but I believe for someone who has some at least average php skill, this will make sense. I cut and pasted this line from a query I am doing against a custom taxonomy myself where I only wanted it to display each term only once.

$terms = array_map("unserialize", array_unique(array_map("serialize", $terms)));