← SQL Operations Cases
Lesson 3 of 4
Flag inventory exceptions
Compare known quantities while separating missing counts.
Do the work
- Low stock means on_hand < reorder_at, strictly.
- NULL on_hand is an unknown count, not zero.
- Equality is not below the reorder point.
See the method
PEN 5 < 10 and MUG 0 < 5 are low.
Read every demonstration step
- PEN 5 < 10 and MUG 0 < 5 are low.
- CARD 4 = 4 is not low under this rule.
- BAG needs a separate recount because its count is NULL.
Practice independently
Exercise 1
Find stock below the reorder point
Open practice →Exercise 2List products needing a recount
Open practice →Take it further
Changing < to <= is a business policy change; keep the stated rule.