Sql 使用 SKU 查询 Woocommerce 订单

Question

通过以下查询，我获得了已完成订单的数据，我想添加由 | 分隔的 SKU 在新列中。 我找不到执行正确连接的方法

select
    p.ID as order_id,
    p.post_date,
    max( CASE WHEN pm.meta_key = '_billing_first_name' and p.ID = pm.post_id THEN pm.meta_value END ) as _billing_first_name,
    max( CASE WHEN pm.meta_key = '_billing_last_name' and p.ID = pm.post_id THEN pm.meta_value END ) as _billing_last_name,
    ( select group_concat( order_item_name separator '|' ) from wp_woocommerce_order_items where order_id = p.ID ) as order_item
from
    wp_posts p 
    join wp_postmeta pm on p.ID = pm.post_id
    join wp_woocommerce_order_items oi on p.ID = oi.order_id
where
    post_type = 'shop_order' and
    post_date BETWEEN '2022-04-01' AND '2022-06-30' and
    post_status = 'wc-completed'
group by
    p.ID