I'm not sure if you get what .values.sum would do:
c = User.group(:role).count
=> {:normal=>3, :admin=>4}
c.values.sum
=> 7
Even a hash with thousands of keys/values would sum its values very fast.
And I don't get what you mean with "is actually changing what would be
counted".
Considering c = User.group(:role).count, c.values.sum would return the
exactly number of records that would be returned and c.keys.sum would
return exactly number of group param that would be returned, no?
On Sun, Sep 14, 2014 at 2:20 AM, Will Bryant <will.bry...@gmail.com> wrote:
> Calling .values.sum might have to load a LOT of (id, count) rows so it
> isn't a very scalable solution.
>
> Calling regroup or something is actually changing what would be counted -
> the group can affect the count, especially if you use HAVING clauses.
>
> There's nothing wrong with having the grouped count functionality, but
> it's messing up the #count API IMHO.
>
>
> On 13/09/2014, at 03:40 , Gabriel Sobrinho <gabriel.sobri...@gmail.com>
> wrote:
>
> I'm against to count and size works equally since I would want to know how
> many grouped records do I have (i.e.: how many roles do I have on
> determining relation).
>
> I think that count and size is working as both should.
>
>
> Although, if you want to count all records of a grouped relation, you have
> to remove the group or just sum the counts:
>
> User.count
>
>
> or:
>
>
>
> User.group(:role).count.values.sum
>
>
> Not elegant but if you can't remove the group for that count, you have to
> do that.
>
>
> One possible option would rails have something like regroup(false) as
> reorder(false), but again I think that just adding the values is more
> easier for everyone :)
>
> On Thursday, September 11, 2014 11:54:14 PM UTC-3, Shinohara Teruki wrote:
>>
>> >> size in this case is an pretty much an "alias" for count, thus it's
>> gonna work the same way as count when grouping.
>>
>> I think that current #size don't behave like an alias for #count.
>>
>> g = User.group(:role); g.load; g.count
>> => {:normal=>3, :admin=>4}
>>
>> g = User.group(:role); g.load; g.size
>> => 2
>>
>> When I call #load before #count or #size, a return value of #count don't
>> equals to a return value of #size.
>>
>>
>> >> Is there any particular reason to know how many records returned if
>> you are grouping?
>>
>> I expect #count and #size to return same value.
>> It is not the case that I want to know how many records the grouping
>> query returns.
>>
>> My ideal implementation:
>>
>> g = User.group(:role); g.load; g.count
>> => {:normal=>3, :admin=>4}
>>
>> g = User.group(:role); g.load; g.size
>> =>{:normal=>3, :admin=>4}
>>
>> or
>>
>> g = User.group(:role); g.load; g.count
>> => 2
>>
>> g = User.group(:role); g.load; g.size
>> =>2
>>
>> What do you think?
>>
>> Thank you
>>
>>
>> 2014年9月12日金曜日 8時21分39秒 UTC+9 Carlos Antonio da Silva:
>>>
>>> size in this case is an pretty much an "alias" for count, thus it's
>>> gonna work the same way as count when grouping.
>>>
>>> Is there any particular reason to know how many records returned if you
>>> are grouping?
>>>
>>> On Wed, Sep 10, 2014 at 11:16 AM, Shinohara Teruki <ts....@gmail.com>
>>> wrote:
>>>
>>>> ActiveRecord::Relation.size returns a Hash when I use a group method.
>>>> I think that a size method is expected to return integer typically.
>>>>
>>>> I propose this implementation:
>>>>
>>>> def size
>>>> if loaded?
>>>> @records.length
>>>> else
>>>> count_value = count(:all)
>>>> count_value.is_a?(Hash) ? count_value.length : count_value
>>>> end
>>>> end
>>>>
>>>> This is a current implementation:
>>>>
>>>> # https://github.com/rails/rails/blob/master/activerecord/lib/active_
>>>> record/relation.rb
>>>> # Returns size of the records.
>>>> def size
>>>> loaded? ? @records.length : count(:all)
>>>> end
>>>>
>>>>
>>>> A count method is implemented on calculations.rb.
>>>> https://github.com/rails/rails/blob/master/activerecord/lib/active_
>>>> record/relation/calculations.rb
>>>>
>>>>
>>>> What do you think?
>>>>
>>>> Thank you
>>>>
>>>> --
>>>> You received this message because you are subscribed to the Google
>>>> Groups "Ruby on Rails: Core" group.
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>>>>
>>>
>>>
>>>
>>> --
>>> At.
>>> Carlos Antonio
>>>
>>
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--
Cheers,
Gabriel Sobrinho
http://gabrielsobrinho.com/
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