I'm writing plugin for syncing prices of WooCommerce products with external source. So I want to get products with EAN (have meta data _wpm_gtin_code). Whaterver I pass to get_posts($args) I get empty data. I'm using WordPress 5.3.2.

I dived into WP source to track why. When I print generated SQL $this->request at wp-includes/class-wp-query.php:2890 I see it contains "where condition" AND (0 = 1) which obviously cannot succeed. This piece of code is inserted by Taxonomies called on wp-includes/class-wp-query.php:2101-2109, explicitly by $clauses = $this->tax_query->get_sql( $wpdb->posts, 'ID' ); $where .= $clauses['where'];.

I didn't dig deeper into $this->tax_query->get_sql(...). What I know is that I don't pass any taxonomy arguments to get_posts($args), so I don't expect it to influence the query.

How shall I call get_posts($args) to get all posts just of some type and status?

        $meta_query = array(
            'relation' => 'OR',
            array(
                'key'       => '_wpm_gtin_code',
                'compare'   => 'EXISTS'
            ),
            array(
                'key'       => '_product_code',
                'compare'   => 'EXISTS'
            )
        );
        $args = array(
            'meta_query' => $meta_query,
            'post_type' => 'product',
            'post_status' => 'publish',
            'posts_per_page' => -1,
        );
        error_log(print_r($args, true)); // print args
        $posts = get_posts( $args );
        error_log(print_r($posts, true)); // print posts - empty!!!

I'm writing plugin for syncing prices of WooCommerce products with external source. So I want to get products with EAN (have meta data _wpm_gtin_code). Whaterver I pass to get_posts($args) I get empty data. I'm using WordPress 5.3.2.

I dived into WP source to track why. When I print generated SQL $this->request at wp-includes/class-wp-query.php:2890 I see it contains "where condition" AND (0 = 1) which obviously cannot succeed. This piece of code is inserted by Taxonomies called on wp-includes/class-wp-query.php:2101-2109, explicitly by $clauses = $this->tax_query->get_sql( $wpdb->posts, 'ID' ); $where .= $clauses['where'];.

I didn't dig deeper into $this->tax_query->get_sql(...). What I know is that I don't pass any taxonomy arguments to get_posts($args), so I don't expect it to influence the query.

How shall I call get_posts($args) to get all posts just of some type and status?

        $meta_query = array(
            'relation' => 'OR',
            array(
                'key'       => '_wpm_gtin_code',
                'compare'   => 'EXISTS'
            ),
            array(
                'key'       => '_product_code',
                'compare'   => 'EXISTS'
            )
        );
        $args = array(
            'meta_query' => $meta_query,
            'post_type' => 'product',
            'post_status' => 'publish',
            'posts_per_page' => -1,
        );
        error_log(print_r($args, true)); // print args
        $posts = get_posts( $args );
        error_log(print_r($posts, true)); // print posts - empty!!!

• meta-query
• get-posts
• tax-query

1 Answer 1

The whole problem was in WooCommerceCategoryExcluder (old, obsolete and unmaintained) plugin which hooks to pre_get_posts and adds taxonomy query to get_posts() args.

Maybe this investigation helps someone else trying to solve similar problem.