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Re: getting the ranks of items

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Randal L. Schwartz wrote:

I'm probably asking a FAQ, but a few google searches didn't seem
to point me in the right place.

Is there a simple way with PostgreSQL to assign relative ranks to the
result of a query ORDER BY?  That is, I want to either have a view
that cheaply assigns the ranks, or be able to update a column with the
current ranks (yes, I know this latter version is more prone to
error).

I'm certain there's probably something I can do to laminate an array
value to a query result.  Am I confused?  (Yes!)




Randal,

May be you can use something like this:


create sequence seq_tmp;
select nextval('seq_tmp') as rank, a.id, a.name from (select id, name from t order by name desc) a;
drop sequence seq_tmp;



I don't know how cheap will this be (because of the sequence), but couldn't find another way. I do not think that we have something like Oracle's ROWNUM...



Regards, Lyubomir Petrov

P.S. I'm sure you can wrap it in plperl stored procedure :)




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