Re: Fwd: Silly question about numbering of rows?

On Tue, 13 Mar 2001, Ken Corey wrote:

> Moderator, please don't approve the other two posts I've made...just this one
> is plenty...;^)

Not a moderated list.

> I have a table like this:
>
> id | make | model | year | value
> ---------+-----------+--------+-------+-------
> 57 | 2 | 0 | 4 | 4750
> 57 | 2 | 3 | 4 | 4750
> 57 | 2 | 0 | 0 | 4750
> 57 | 2 | 0 | 3 | 4750
> 57 | 2 | 3 | 0 | 4750
> 57 | 2 | 3 | 3 | 4750
> 2 | 2 | 0 | 3 | 4750
> 2 | 2 | 3 | 3 | 4750
> 2 | 2 | 0 | 4 | 4350
> 2 | 2 | 3 | 4 | 4350
> 2 | 2 | 0 | 0 | 4750
> 2 | 2 | 0 | 5 | 4750
> 2 | 2 | 3 | 0 | 4750
> 2 | 2 | 3 | 5 | 4750

The potential for duplicate records is rampant here. What is the primary
key? Do these values use foreign keys?

> Everything is working swimmingly, except for the numbering magic. As you can
> see there are several variations of data in that table, so I can't use a
> serial on the table directly.

Why not? The serial number can be used exclusively for identifying a
unique row. That's definitely the easiest way to do this numbering.

> Further, this table is likely to change on a minute by minute basis, so I
> don't want to create a permanent numbering that will just have to be changed.

Ah, that is a problem.

> It sounds easiest to me to just punt and number the rows as they are returned
> in my calling application...

That might be the way to go, if the ordering and numbering is changing
constantly.

-- Brett
http://www.chapelperilous.net/~bmccoy/
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