Let's say I have the following contrived schema:
TRANSPORTATION_MODE
modeID serial
model_number text
AIRPLANE
airplaneID serial
operational_ceiling int
modeID int FK
AUTOMOBILE
automobileID serial
cruising range int
modeID int FK
Of course, being an airplane and being an automobile are mutually exclusive.
How does one program the mutual exclusivity in PostgreSQL? I've studied using
check contraints, triggers, and rules, but I'm not finding any obvious way to
program this.