Orders can have several statuses in WooCommerce; completed, processing, on-hold, pending to name a few.

In WooCommerce 2.1, statuses were associated with orders via a taxonomy called shop_order_status. The shop_order_status taxonomy is no more in 2.2.

Instead, 2.2 uses post_status for the order status. In terms of usage, this makes more sense – regular post statuses are of little use for orders (since when did you have a non-published order?). For performance, using post status has several benefits, particulary to queries and reporting which can now contain less table joins.

How does this affect developers? If you query shop_order posts via a get_posts() function, or DB query, you will need to modify your code to fully support 2.2. Otherwise you’ll either get a notice, or no results.

If you are calling get_posts() for the shop_order post type

Here is an example of a 2.1 order query:

$orders = get_posts( array(
        'post_type'   => 'shop_order',
        'post_status' => 'publish',
        'tax_query'   => array( array(
                'taxonomy' => 'shop_order_status',
                'field'           => 'slug',
                'terms'         => array( 'processing', 'completed' )
        ) )
) );

This query uses shop_order_status which will no longer work in 2.2 without throwing a notice. For 2.2 you’d change this to be:

$orders = get_posts( array(
        'post_type'   => 'shop_order',
        'post_status' => array( 'wc-processing', 'wc-completed' )
) );

If you wanted to get all orders, of any status, 2.2 has a function wc_get_order_statuses() which returns all registered order statuses:

$orders = get_posts( array(
        'post_type'   => 'shop_order',
        'post_status' => array_keys( wc_get_order_statuses() )
) );

If you are doing $wpdb queries on shop_order posts

Like above, you’ll need to change the taxonomy part of your query. Here is an example from 2.1:

$sales = $wpdb->get_var( "SELECT ID FROM {$wpdb->posts} as posts
            LEFT JOIN {$wpdb->term_relationships} AS rel ON posts.ID=rel.object_ID
            LEFT JOIN {$wpdb->term_taxonomy} AS tax USING( term_taxonomy_id )
            LEFT JOIN {$wpdb->terms} AS term USING( term_id )
            WHERE   posts.post_type     = 'shop_order'
            AND     posts.post_status   = 'publish'
            AND     tax.taxonomy        = 'shop_order_status'
            AND     term.slug           IN ( '" . implode( "','", array( 'completed', 'processing', 'on-hold' ) ) . "' )
        " );

In 2.2, this becomes:

$sales = $wpdb->get_var( "SELECT ID FROM {$wpdb->posts} as posts
            WHERE   posts.post_type     = 'shop_order'
            AND     posts.post_status   IN ( '" . implode( "','", array( 'wc-completed', 'wc-processing', 'wc-on-hold' ) ) . "' )
        " );

Direct queries on the database will need to be updated, or no results will be returned.