10A
Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
-- 10a: Find unknown customer references
SELECT r.batch_row,r.customer_id FROM aabha_sql.raw_orders AS r
LEFT JOIN aabha_sql.customers AS c ON c.customer_id=r.customer_id
WHERE r.customer_id IS NOT NULL AND c.customer_id IS NULL ORDER BY r.batch_row;