Thread: Fwd: Silly question about numbering of rows?

Fwd: Silly question about numbering of rows?

From
Ken Corey
Date:
Hi All,

I haven't posted a silly question in a while, and didn't want to break my
streak...

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
 

I want to be able to select from this table like this:

select<numbering magic>, id, value frommytablewheremake=2model=3and year=5order by score desc;

which would return this:
nbring |        id | value
-------+---------+-------      1 |       57 |  4750      2 |         2 |  4350

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.

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.

I thought about creating a temporary table with a serial and selecting into
that so that a numbering is created and then returning rows from that, but
that sounds like much busywork for the database.

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

What's the best approach here?

--
Ken Corey, CTO    Atomic Interactive, Ltd.   ken.corey@atomic-interactive.com


Re: Fwd: Silly question about numbering of rows?

From
Peter Eisentraut
Date:
Ken Corey writes:

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

The rows are automatically numbered.  In libpq, you'd use
PQgetvalue(result, rownumber, fieldnumber).  Other interfaces have similar
functions.  If the interface has a "fetch"-like approach, it seems trivial
to keep a counter.

-- 
Peter Eisentraut      peter_e@gmx.net       http://yi.org/peter-e/