Out of stock everywhere
Find items that are out of stock in every warehouse that carries them, and items no warehouse carries. Return `sku`, alphabetically.
What a strong answer looks like
Say what the query is meant to return before you write it, and name the shape of the answer: how many rows, grouped by what. Then watch the NULLs and the duplicates, because that is where most of these are lost.
Run onlyA query runs as one statement, so there is nothing to step through. Run it and read the rows.
0:00 of about 14 min
query.sql
Expected, in this order
| sku |
|---|
| MS-2 |
Your result
Run your query to compare.
1 more set of rows are waiting. Free with an account.
Run or narrate your approach, then ask the coach.