Question

I’m learning SQL for a while and I’m stuck with this problem.

I have two tables for a storage company.
In one table for the bookings for the whole company consisting booking no., date, product nr., quantity and storage room.

And in one table I have storage facility name and storage rooms to define the room belong to which facility

I want to have the sum of the quantity of one specific product in one specific storage facility

SELECT sum(Quantity) from Bookings where ProductNo=8888 and Storage.StorageFacility="Central"

Do I have to use a more complex query for the solution?

Answer 1

Your storage facility is in a different table than the BOOKINGS table (and they are related via STORAGE_ROOM). So you need to join these tables:

select sum(Quantity)
  from bookings b 
  join storage_facility_details sfd 
    on b.storage_room = sfd.storage_room
 where sfd.storage_facility = 'x'
   and bookings.productno='8888'