Retrieve WooCommerce products without images using SQL

products-without-images.sql

SELECT 
    p.ID          AS product_id,
    sku.meta_value AS sku
FROM wp_posts        AS p
LEFT JOIN wp_postmeta AS sku
       ON sku.post_id = p.ID 
      AND sku.meta_key = '_sku'
LEFT JOIN wp_postmeta AS thumb
       ON thumb.post_id = p.ID 
      AND thumb.meta_key = '_thumbnail_id'
WHERE
    p.post_type  = 'product'
    AND thumb.meta_value IS NULL
ORDER BY p.ID;