How to fix SQL query?

Question

SQL

There are three tables. rpm_zone_future_retail, rpm_future_retail, and rpm_zone_location A
search query is needed to find all item/zone combinations in the rpm_zone_future_retail table for which there is no location-level price data (rpm_future_retail). That being said, the locations associated with each zone can be retrieved from the rpm_zone_location table (eg: zone: 1 = locations: 2302, 3040, etc.). The conclusion should be the following


. So far, I have only comprehended this

select rpm_zone_future_retail.*
from rpm_zone_future_retail
join rpm_future_retail
on rpm_zone_future_retail. item = rpm_future_retail. item
join rpm_zone_location
on rpm_zone_location. ZONE_ID = rpm_zone_future_retail. ZONE

If this is correct, then how to filter the data to only show those for which there is no data in the rpm_future_retail table

example tables here