Custom field and category query

Question

I have created custom .php file that should show list of all posts that correspond to user's choice. I have 3 custom fields and 1 category condition. I've tried all the queries i could possibly find in wordpress codex database but nothing seems to work.

I've created 3 custom fields: a_field,a_fieldd,a_fielddd (and ofcourse i have posts with those fields already posted for the test) now I just want to show all of the posts with custom fields with specified values (user's choice) and only if those posts are inside the chosen category

EDIT

I have a query (with just 1 value for test), which seems to be working, but sometimes takes 0,00002s someties up to 4 seconds. any suggestions? I know it would be better if I use wp_query but I found this way to be easier to modify. in this example i am trying to get the post with meta_key a_field with value "5"

SELECT wp_posts.ID FROM wp_posts 
INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id)
INNER JOIN wp_postmeta AS mt1 ON (wp_posts.ID = mt1.post_id)
INNER JOIN wp_postmeta AS mt2 ON (wp_posts.ID = mt2.post_id)
WHERE 1=1 AND wp_posts.post_type = 'post' 
AND wp_posts.post_status = 'publish'
AND ( (wp_postmeta.meta_key = 'a_field' 
AND  find_in_set('5',wp_postmeta.meta_value)) ) 
GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 10  

any suggestions?

Answer 1

For multiple category handling you need either category__in or a tax_query, for multiple custom fields you use meta_query. The various options for both of these are covered in the WP_Query codex page.

$args = array(
    'posts_per_page' => 10,
    'category__in' => array( 163, 165 ),
    'meta_query' => array(
        array(
            'key' => 'a_field',
            'value' => array( 1, 2 ),
            'compare' => 'IN'
        ),
        array(
            'key' => 'a_fieldd',
            'value' => 3,
            'compare' => '='
        ),
        array(
            'key' => 'a_fielddd',
            'value' => array( 1, 3, 5 ),
            'compare' => 'IN'
        )
    )
);
$results = new WP_Query( $args );

if( $results->have_posts() ){
    while( $results->have_posts() ){
        $results->the_post();
        the_title();
    }
}