From: Logan Capaldo <logancapaldo@...>
Date: 2006-08-04T01:09:05+09:00
Subject: Re: Array#size empties the Array??


On Aug 3, 2006, at 12:00 PM, Sven Suska wrote:

> Yukihiro Matsumoto wrote:
>> Sven Suska writes:
>>
>> |Sorry, I had forgotten to give enough information:
>>
>> This is not enough.  Could you show us a whole script to reproduce  
>> the
>> problem?
>
> Yes I know it would be useful, but it's hard to find and extract the
> relevant
> parts.
>
>> I am sure your expectation of "exactly same" fails
>> somewhere.
>
> Well, sorry to say that, but I think your assumption is not correct.
>
>
>
> Let's see if my new findings give anybody a clue.
>
>
> At first I tried a different ActiveRecord version - no difference.
>
> Then I put some debug printouts into AR and I found clearly different
> behaviour.
> I'll just give the raw output,
> even if I don't tell you what the printout statements were,
> you can see the difference clearly:
>
>
> 1. #length first:
> ================
>
> ** RUBY_VERSION = "1.8.4"
> ** "ar-svs: args=[:all]"
> ** [:SVSAR_find_sql, "SELECT * FROM rkScGla WHERE (rkScGla.vsnr =
> 'GK_715') AND (rkScGla.komp = 'R1') AND (rkScGla.vtnr = 1) "]
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> [:rks_length, 31]
> [:rks_size, 31]
> [:rks_class, Array]
> [:rks_item, #<Rk:0x16344d8 @attributes={"rzvk"=>0.0, ...}>]
> [:rks_length, 31]
> [:rks_size, 31]
>
>
>
> 2. #size first:
> ===============
>
> ** RUBY_VERSION = "1.8.4"
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> ** "tn=rkScGla"
> ** :vor_newtable
> ** :nach_newtable
> ** [:SVSAR_sel_1_sql, "SELECT count(*) AS count_all FROM rkScGla WHERE
> (rkScGla.vsnr = 'GK_715' AND rkScGla.komp = 'R1' AND rkScGla.vtnr =  
> 1) "
> [:rks_size, 0]
> [:rks_length, 0]
> [:rks_class, Array]
> [:rks_item, nil]
> [:rks_length, 0]
> [:rks_size, 0]
>
>
>
> ---> This looks like a very exciting ActiveRecord hack!!!
>
> It looks like rks is something special in the beginning,
> that will be replaced by the real array as soon as methods are
> being sent to it.
>
> Well, whatever the explanation may be, it has become clear now,
> that this behaviour is caused by ActiveRecord, and so I should
> repost the issue in the rails forum.
>
> And now I understand why this issue has not bothered anybody before,
> it has only come up because my hand-written database-adapter is not
> yet able to execute the "SELECT count(*) ..." statement correctly.
>
>
> OK... Exciting day, today...
>
>
> Thank you all for your support
>
>
> Regards
>
> Sven
>
>

AR does all sorts of magic. It has been my experience that whenever  
something doesn't work as it should or as I expect and I am making  
use of AR, AR is probably the culprit.

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