Rails - Aug 2006 - Noob Q: How to make list of cat's from selected items?

I have a table of items linked to a table of categories much like the 
cookbook demo.

I''m currently aking a search function for the list, with pagination.

Would like to include on the page a list of categories, with #''s of 
each, for the displayed items.

I know I could iterate over the list using:

@item.each do

and some code to make a list of item.category.title''s with incriments 
for each occurance.

But I''m thinking there has to be a more eligant Ruby way of doing this,
that I just can''t see right now.

Hints, tips and pointers to simular code most welcome.

Lance. F. Squire

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On 8/23/06, Lance Squire
<rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
>
> I have a table of items linked to a table of categories much like the
> cookbook demo.
>
> I''m currently aking a search function for the list, with
pagination.
>
> Would like to include on the page a list of categories, with #''s
of
> each, for the displayed items.
>
> I know I could iterate over the list using:
>
> @item.each do
>
> and some code to make a list of item.category.title''s with
incriments
> for each occurance.
>
> But I''m thinking there has to be a more eligant Ruby way of doing
this,
> that I just can''t see right now.
>
> Hints, tips and pointers to simular code most welcome.
For a given category, you should be able to get the number of
associated Items with something like the following:

Item.count(["category_id = ?", id])

That''s going to trigger a SQL query every time it''s called, so
if you
have a lot of categories then you might want to use custom SQL to
fetch all the counts at once.

-- James

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James Ludlow wrote:
> 
> Item.count(["category_id = ?", id])
> 
> That''s going to trigger a SQL query every time it''s
called, so if you
> have a lot of categories then you might want to use custom SQL to
> fetch all the counts at once.
> 
> -- James
Ya, I was thinking I could count the ones already collected in the @item 
list, rather than re-quering the database.

Woulden''t the above just give me the total number of items of that 
category in the database? Rather than in my pre selected list?

Lance

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