Richard Huxton wrote:
>
>> CREATE TABLE car_tags
>> (
>> CarID integer NOT NULL,
>> TagID integer NOT NULL
>> );
> [snip other table defs]
>
> Don't forget CarID isn't really an integer (I mean, you're not going to
> be doing sums with car id's are you?) it's actually just a unique code.
> Of course, computers are particularly fast at dealing with 32-bit integers.
Just realised I haven't explained what I meant by that.
CarID is a different type from PlaneID and TagID. As it happens, we are
using integers to represent them all, but a CarID = 1 is different from
a PlaneID = 1 and although you can numerically compare the two it is an
error to do so.
--
Richard Huxton
Archonet Ltd
