Hello, I’m struggling to understand on how to answer the question on Screen 6 of Guided Project: Answering Business Questions using SQL
My problem is this one, if you use this code:
SELECT invoice_id, album_id FROM invoices_info GROUP BY invoice_id
And group by invoice_id without aggregation you lose around 70% of all information because it acts like
DISTINCT in this case. Could someone explain me what’s the logic behind the solution? What am I supposed to compare?