On 4/8/08, Craig Ringer <craig@postnewspapers.com.au> wrote:
> novice wrote:
>
> > Is it possible to write a query to produce:
> >
> > meter_id | no_of_bays | bay_id
> > ----------+------------+-----------
> > 5397 | 2 | 5397-01
> > 5397 | 2 | 5397-02
> > 5409 | 3 | 5409-01
> > 5409 | 3 | 5409-02
> > 5409 | 3 | 5409-03
>
> Sure. One way, not necessarily a particularly clever or efficient way,
> is to do a join with:
>
> generate_series(1, (select max(no_of_bays) from meter)) as i
>
> and use a WHERE clause to select for `i <= no_of_bays'
You have a problem, and it's bad design.
A bad design leads to these types of kludges.
Consider re-engineering your schema.
In any case, good luck.
