Re: SQL PUZZLE: selecting top 50 salaries in a table

NOPE. The rownum pseudo column is populated as the rows are returned from the the query and this is BEFORE the order by is applied. This very simple solution is proposed almost very time a question is raised on returning the (TOP/BOTTOM) N Rows of a table.

Van Messner’s solution does not work on my 7.3.4 installation. The SELECT as a column does not cut it in Oracle 7, I don’t know about Oracle 8.

If you do not want to do this in PL*SQL (the “easiest” solution). Then you may try this code. Please note, it is not very fast. If you only need the salary and rank, then the inline view is all that is needed.

SELECT rank.ranking, sal1.salary, sal1.{other info} FROM MySalaryTable sal1,
 (SELECT sala.salary, COUNT(distinct salb.salary) Ranking   FROM MySalaryTable sala, MySalaryTable salb   WHERE sala.salary <= salb.salary
    AND salb.determinant = salb.determinant   GROUP BY sala.salary) rank
WHERE sal1.salary = rank.salary
  AND ranking <= &n
ORDER BY Ranking

HTH
    James

In article <38102EEB.90C8C627_at_it.lv>,
  Maris Gabalins <mg_at_it.lv> wrote:
> select salary
> from ....
> where rownum < 51
> order by salary desc
>
> Van Messner wrote:
>
> > I don't have Oracle in front of me but please try below where n is
how many
> > top records to select, MySalaryTable has the salary information and
> > determinant is any other condition (the 50 top salaries for 1997 for
> > example). This query should allow for ties, which in the case of
salaries,
> > are likely to occur.
> >
> > SELECT
> > sal1.salary,
> > (SELECT
> > COUNT(DISTINCT salary)
> > FROM
> > MySalaryTable sal2
> > WHERE
> > sal2.salary >= sal1.salary
> > and sal2.determinant = sal1.determinant) as ranking
> > FROM
> > MySalaryTable sal1
> > Where
> > ranking <= &n
> > ;
> >
> > Van
> >
> > NetComrade <andreyNSPAM_at_bookexchange.net> wrote in message
> > news:380f8e89.268436409_at_news.earthlink.net...
> > > Well.. we know how to select top salary, which is select
max(salary),
> > > but how would I select top 50 records?
> > > ---------------
> > > Andrey Dmitriev eFax: (978) 383-5892 Daytime: (917) 373-5417
> > > AOL: NetComrade ICQ: 11340726 remove NSPAM to email
> > >
>
>

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Before you buy. Received on Fri Oct 22 1999 - 11:12:09 CDT