Tax Query trouble

Question

I can't seem to figure this out.

The following query works:

$xxxx = new WP_Query(array(
'listset' => 'homepage',
'meta_query' => array(
    array (
        'key' => 'show_home',
        'value' => 'true',
        'compare' => '='
    )
),
'posts_per_page' => 1,
'post_type' => 'lists',
'post_status' => 'publish',
'orderby' => 'date',
'order' => 'DESC'
));

The following does not:

$xxxx = new WP_Query(array(
'tax_query' => array(
    array (
        'taxonomy' => 'listset',
        'field' => 'slug',
        'terms' => 'homepage'
    )
),
'meta_query' => array(
    array (
        'key' => 'show_home',
        'value' => 'true',
        'compare' => '='
    )
),
'posts_per_page' => 1,
'post_type' => 'lists',
'post_status' => 'publish',
'orderby' => 'date',
'order' => 'DESC'
));

Anyone can help me figure out why the second one doesn't work?

Answer 1

The terms for the tax_query should be an array.

Answer 2

You say that "the second one doesn't work", but it's not clear in what way it doesn't work, and in what way you expect it to work. The query you've put together will only match posts that BOTH have listset = 'homepage' AND show_home = 'true'. Are you sure that there are posts in your database where this is true? Is this what you mean to be querying?

I don't think that it's possible to do an OR between meta_query and tax_query using WP_Query alone. You would probably have to either do two queries (the first would give the post__in parameter for the second) or filter posts_where and do some fancy regex.