How do you search for a post by custom taxonomy?

Question

I'm trying to search for the latest post that has a custom taxonomy attached to it. I've used the Advanced Custom Fields plugin to add a custom taxonomy called 'brand_post_link' which allows users to tag a blog post with a brand, which is a taxonomy used with Woocommerce called 'product_brand'.

I have a product_brand taxonomy archive where I list all product brands and individual product brand pages which list all the products in that brand. What I then want to do is get the latest blog post which is tagged with that brand.

Here is the code I have to get all products for a brand used on the individual brand page:

$brandData = get_queried_object();
$args = array(
    'post_type' => 'product',
    'post_status' => 'publish',
    'ignore_sticky_posts' => 1,
    'posts_per_page' => 12,
    'tax_query' => array(
        array(
            'taxonomy' => 'product_brand',
            'field' => 'id',
            'terms' => $brandData->term_id
            )
        )
);
$brandProducts = new WP_Query($args);

This works fine, so here is the code I thought would work to get the most recent post for the specific brand:

$relatedBlogPostArgs = array(
    'post_type' => 'post',
    'post_status' => 'publish',
    'posts_per_page' => 1,
    'order' => 'DESC',
    'orderby' => 'date',
    'tax_query' => array(
        array(
            'taxonomy' => 'brand_post_link',
            'field' => 'id',
            'terms' => $brandData->term_id
        )
    )
);
$relatedBlogPosts = new WP_Query($relatedBlogPostArgs);

This however doesn't return anything. Is there a fault in my logic or code somewhere or is the code correct and simply a case of matching up the correct name/id/taxonomy etc?

Answer 1

For the record I found an answer to this question in the end - I needed to use a meta query rather than a taxonomy query. The correct code ended up being this:

$relatedBlogPostArgs = array(
    'post_type' => 'post',
    'post_status' => 'publish',
    'posts_per_page' => 1,
    'order' => 'DESC',
    'orderby' => 'date',
    'meta_query' => array(
        array(
            'key' => 'brand_post_link',
            'value' => $brandData->term_id
        )
    )
);
$relatedBlogPosts = new WP_Query($relatedBlogPostArgs);