Aaron Cooper wrote: > An example of what has caused my concern here is a table called > "Devices" which will store information on individual physical electronic > devices. He has made the primary keys DeviceID, CustomerID, CountryID > and DeviceTypeID. > > This seems to be a massive overkill even in my limited DB design > experience. Each device will appear only once in this table, so why is > the DeviceID not good enough alone?
Correct, if DeviceID is guaranteed unique, then the key listed above isn't a candidate key and shouldn't be the primary key. Instead, DeviceID is the obvious primary key. -- E|2 DIGITAL TIM OLIVER SOFTWARE ENGINEER P +64 3 377 0007 F +64 3 377 6582 E [email protected] www.e2digital.co.nz -- NZ PHP Users Group: http://groups.google.com/group/nzphpug To post, send email to [email protected] To unsubscribe, send email to [email protected]
