Rails - Jan 2006 - "Selecting" a calculated row / Using :select in the paginate method

Hi,

I was trying to use the :select parameter to select a calculated row, 
but it appears that the parameter is not picked up by the paginate method.

I want to add the following to the select statement:

timediff(now(), created_on) as age

So I tried:

@story_pages, @stories = paginate :stories, {:per_page => 10, :include 
=> ''user'', :select => ''timediff(now(),
story.created_on) as story_age''}

... to no avail.

I know I can create a method named "age" for the story model that can 
retrieve that calculation, but that''s a query for each element, so
it''s
very undesirable.

In case you''re wondering why I don''t calculate the
"age" inside my Rails
app, check this blog:

http://railsexpress.de/blog/articles/2005/11/09/accelerate-your-dates

If you know of a solution or alternative, I''ll greatly appreciate your
help.

Sincerely,
Ivan V.

Iv?n Vega Rivera wrote:
> @story_pages, @stories = paginate :stories, {:per_page => 10, :include
> => ''user'', :select => ''timediff(now(),
story.created_on) as story_age''}
> 
> ... to no avail.
I''m somewhat sure that paginate (and find for that matter)
don''t know
what to do with the :select option.

Try using find_by_sql()

-- 
Posted via http://www.ruby-forum.com/.

Check out this code snippet:
http://bigbold.com/snippets/posts/show/389
Even better is the updated version in ''toolmantim''s''
post at the bottom.

On 1/5/06, Iv?n Vega Rivera <ivanvega@gmail.com>
wrote:
> Hi,
>
> I was trying to use the :select parameter to select a calculated row,
> but it appears that the parameter is not picked up by the paginate method.
>
> I want to add the following to the select statement:
>
> timediff(now(), created_on) as age
>
> So I tried:
>
> @story_pages, @stories = paginate :stories, {:per_page => 10, :include
> => ''user'', :select => ''timediff(now(),
story.created_on) as story_age''}
>
> ... to no avail.
>
> I know I can create a method named "age" for the story model that
can
> retrieve that calculation, but that''s a query for each element, so
it''s
> very undesirable.
>
> In case you''re wondering why I don''t calculate the
"age" inside my Rails
> app, check this blog:
>
> http://railsexpress.de/blog/articles/2005/11/09/accelerate-your-dates
>
> If you know of a solution or alternative, I''ll greatly appreciate
your help.
>
> Sincerely,
> Ivan V.
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

Thanks!

Wilson Bilkovich wrote:
> Check out this code snippet:
> http://bigbold.com/snippets/posts/show/389
> Even better is the updated version in
''toolmantim''s'' post at the bottom.
>
> On 1/5/06, Iv?n Vega Rivera <ivanvega@gmail.com> wrote:
>   
>> Hi,
>>
>> I was trying to use the :select parameter to select a calculated row,
>> but it appears that the parameter is not picked up by the paginate
method.
>>
>> I want to add the following to the select statement:
>>
>> timediff(now(), created_on) as age
>>
>> So I tried:
>>
>> @story_pages, @stories = paginate :stories, {:per_page => 10,
:include
>> => ''user'', :select => ''timediff(now(),
story.created_on) as story_age''}
>>
>> ... to no avail.
>>
>> I know I can create a method named "age" for the story model
that can
>> retrieve that calculation, but that''s a query for each
element, so it''s
>> very undesirable.
>>
>> In case you''re wondering why I don''t calculate the
"age" inside my Rails
>> app, check this blog:
>>
>> http://railsexpress.de/blog/articles/2005/11/09/accelerate-your-dates
>>
>> If you know of a solution or alternative, I''ll greatly
appreciate your help.
>>
>> Sincerely,
>> Ivan V.
>>
>> _______________________________________________
>> Rails mailing list
>> Rails@lists.rubyonrails.org
>> http://lists.rubyonrails.org/mailman/listinfo/rails
>>
>>     
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>

Check 
http://railsexpress.de/blog/articles/2005/11/06/the-case-for-piggy-backed-attributes
;-)

Kevin Olbrich wrote:
> Iv?n Vega Rivera wrote:
>   
>> @story_pages, @stories = paginate :stories, {:per_page => 10,
:include
>> => ''user'', :select => ''timediff(now(),
story.created_on) as story_age''}
>>
>> ... to no avail.
>>     
>
> I''m somewhat sure that paginate (and find for that matter)
don''t know
> what to do with the :select option.
>
> Try using find_by_sql()
>
>