SQL database self interaction entity
- by Ricardo Costa
I've been working on a database, wich is referent to an Aeroport management. I'm having a problem that it's freaking me out.. What i'm trying to do is, assuming that a client wants to know the distance between 2 locations, in miles or kms.
As an example, if the user wants to know the distance between London and Amsterdam, should that distance be calculated by a formule or should it be already stored on the database?
(1,N) ____________
____________|__ |
| | |
| City/Airport |<---------|
|______________|
How can i show to user the distance between his 2 choices?
RicardoCosta