Rails - Sep 2005 - how to paginate search results?

Heya,

what is a good way to paginate search results? I created a search method
for my models, which even accepts :limit and :offset like the find
methods but I can''t think of a good solution for this chicken and egg
problem:

@modl_pages = Paginator.new self, modl_count, 20,
@params[''page'']
sql = modl_pages.current.to_sql
@modls = Modl.search(:all, :query => @query, :limit => sql[0], :offset
=> sql[1])

how do I get the count for the Paginator.new without performing the
search? Or rather how do I avoid doing the search twice?

Putting the count in the session is the only solution I can think of
right now, so that only for the first page the search has to performed
twice.


thanks,
Florian

On 9/4/05, Florian Munz <surf-SFNkG+ShufSELgA04lAiVw@public.gmane.org>
wrote:
> Heya,
> 
> what is a good way to paginate search results?
def search
    nt = Note.search(params[:q])
    @pages = Paginator.new self, nt.size,
NOTES_CONFIG[''notes_per_page''], @params[:page]
    first = @pages.current.offset
    last = [first + NOTES_CONFIG[''notes_per_page''],
nt.size].min
    @notes = nt[first...last]
end

Stoyan Zhekov <stoyan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> def search
>     nt = Note.search(params[:q])
>     @pages = Paginator.new self, nt.size,
> NOTES_CONFIG[''notes_per_page''], @params[:page]
>     first = @pages.current.offset
>     last = [first + NOTES_CONFIG[''notes_per_page''],
nt.size].min
>     @notes = nt[first...last]
> end
yeah, I''ve thought about that but didn''t like the idea of
having the
whole -- problably huge -- search result set in memory.

There must be a better way ;-)


Florian

On søn, 2005-09-04 at 19:55 +0200, Florian Munz wrote:
> Stoyan Zhekov <stoyan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
> > def search
> >     nt = Note.search(params[:q])
> >     @pages = Paginator.new self, nt.size,
> > NOTES_CONFIG[''notes_per_page''], @params[:page]
> >     first = @pages.current.offset
> >     last = [first + NOTES_CONFIG[''notes_per_page''],
nt.size].min
> >     @notes = nt[first...last]
> > end
> 
> yeah, I''ve thought about that but didn''t like the idea of
having the
> whole -- problably huge -- search result set in memory.
> 
> There must be a better way ;-)
Don''t know what db you''re using, but how about running a
select count(*)
on the original select query? 

i.e. 

	select count(*) from (select a, b, c, d from table);

Atleast I think that should be possible in Oracle.

Regards,
Henning Pedersen