Rails core - Jul 2013 - Why last doesn't return an ActiveRecord::Relation

Hello,

Sorry if this has been still answered, I haven''t found nothing on it. I
would love to know why ActiveRecord::Base#last doesn''t return an 
ActiveRecord::Relation just like all or where since an 
ActiveRecord::Relation can act more or less like an array (as specified
here<https://github.com/rails/rails/commit/0a6833b6f701c8c8febadfe2f45e25df29493602>
)?

Thanks, have a nice day.

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Because you won''t need to run a query on one element?


On Wed, Jul 17, 2013 at 11:33 AM, Robin Dupret
<robin.dupret@gmail.com>wrote:
> Hello,
>
> Sorry if this has been still answered, I haven''t found nothing on
it. I
> would love to know why ActiveRecord::Base#last doesn''t return an
> ActiveRecord::Relation just like all or where since an
> ActiveRecord::Relation can act more or less like an array (as specified
>
here<https://github.com/rails/rails/commit/0a6833b6f701c8c8febadfe2f45e25df29493602>
> )?
>
> Thanks, have a nice day.
>
> --
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>
>


-- 
Mohamed Wael Khobalatte

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On Jul-19-2013, at 8:08 PM, Mohamed Wael Khobalatte
<wael.khobalatte@gmail.com> wrote:
> Because you won''t need to run a query on one element? 

I think the question is more about Model.last(5) or Model.first(5)

These return arrays when they could return a relation.
--
Tejas Dinkar
http://www.nilenso.com
Nilenso Software (formerly C42 Engineering)

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"first" and "last" have always returned an instance of the
model. These are
meant to be the final method that you call on a relation, to get the 
result. If you call "last(5)" it will return an array, and
that''s the
correct behaviour since that''s the result of the query. If you need the
relation so you can add other criteria on top of it, you can still use 
"limit(5).order(arel_table[:id].desc)"

Andrew Vit


On Wednesday, July 17, 2013 8:33:52 AM UTC-7, Robin Dupret
wrote:
>
> Hello,
>
> Sorry if this has been still answered, I haven''t found nothing on
it. I
> would love to know why ActiveRecord::Base#last doesn''t return an 
> ActiveRecord::Relation just like all or where since an 
> ActiveRecord::Relation can act more or less like an array (as specified 
>
here<https://github.com/rails/rails/commit/0a6833b6f701c8c8febadfe2f45e25df29493602>
> )?
>
> Thanks, have a nice day.
>
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Gotcha. In this case, since calls to Model.last(n) is inherently
inefficient (loading everything and placing a limit), it''s good to keep
it
till the end of the chain.


On Fri, Jul 19, 2013 at 11:55 AM, Tejas Dinkar
<tejasdinkar@gmail.com>wrote:
> On Jul-19-2013, at 8:08 PM, Mohamed Wael Khobalatte <
> wael.khobalatte@gmail.com> wrote:
>
> Because you won''t need to run a query on one element?
>
>
> I think the question is more about Model.last(5) or Model.first(5)
>
> These return arrays when they could return a relation.
> --
> Tejas Dinkar
> http://www.nilenso.com
> Nilenso Software (formerly C42 Engineering)
>
>  --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Core" group.
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>
>


-- 
Mohamed Wael Khobalatte

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"last(5)" is, with regard to efficiency, equivalent to
"limit(5).to_a".


On Fri, Jul 19, 2013 at 2:28 PM, Andrew Vit <andrew@avit.ca> wrote:
> "first" and "last" have always returned an instance of
the model. These
> are meant to be the final method that you call on a relation, to get the
> result. If you call "last(5)" it will return an array, and
that''s the
> correct behaviour since that''s the result of the query. If you
need the
> relation so you can add other criteria on top of it, you can still use
> "limit(5).order(arel_table[:id].desc)"
>
> Andrew Vit
>
>
>
> On Wednesday, July 17, 2013 8:33:52 AM UTC-7, Robin Dupret wrote:
>>
>> Hello,
>>
>> Sorry if this has been still answered, I haven''t found nothing
on it. I
>> would love to know why ActiveRecord::Base#last doesn''t return
an
>> ActiveRecord::Relation just like all or where since an
>> ActiveRecord::Relation can act more or less like an array (as specified
>>
here<https://github.com/rails/rails/commit/0a6833b6f701c8c8febadfe2f45e25df29493602>
>> )?
>>
>> Thanks, have a nice day.
>>
>  --
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>
>
>
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