SQL database self interaction entity

Posted by Ricardo Costa on Stack Overflow See other posts from Stack Overflow or by Ricardo Costa
Published on 2012-12-16T22:46:50Z Indexed on 2012/12/16 23:03 UTC
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entity-relationship

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

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