SQL: WooCommerce product IDs by stock status and backorders

WooCommerce_product_IDs_by_stock_status_and_backorders.sql

SELECT _stock, _stock_status, _backorders, GROUP_CONCAT( PID ) 
FROM (

  SELECT
    post_id AS PID,
    meta_value AS _stock,
  
  (
    SELECT meta_value
    FROM wp_postmeta
    WHERE post_id = PID
    AND meta_key =  '_stock_status'
  ) _stock_status,
  
  (
    SELECT meta_value
    FROM wp_postmeta
    WHERE post_id = PID
    AND meta_key =  '_backorders'
  ) _backorders
  
  FROM  `wp_postmeta` 
  WHERE meta_key =  '_stock'
  ) v

GROUP BY _stock, _stock_status, _backorders