Rails - Jul 2006 - -Infinity for Doule type column

Hi list.

I''m writing a program that stores a lot of Floats into MySQL database. 
Simplified version of the program use the following form of class.

class Val < ActiveRecord::BASE
end

And Vals table contains one column:

num double

One of my data contains -Infinity for num and when I try to
Val.new
Val.num = <- Here goes -Inifinity
Val.save!

Then the program crashes: 
"/usr/local/stow/ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active_record/connection_adapters/abstract_adapter.rb:120:in
`log'': Mysql::Error: Unknown column ''Infinity'' in
''field list'': INSERT
INTO full_doc_indices (`etf`, `Id`, `phonemes`, `filename`, `end_time`, 
`start_time`) VALUES(-Infinity, NULL, ''IH N T IH'',
''BN99EN_2'',
4952.77044, 4939.515) (ActiveRecord::StatementInvalid)"

Obviously, ActiveRecord is using "-Infinity" literally, and then MySQL
treats "-Infinity" as column name as the message shows. How can I
handle
-Infinity then? I really have to store -Infinity anyway.

Thanks.

Sincerely,
Minkoo Seo

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

Ruby does not seem to have a good way of representing infinity in  
floats.  "(1.0/0.0).inifinite?" is more about checking an overflow.

One solution would be to create another column in the table called  
inifinity that could be 0 for not infinite, 1 for positive infinity,  
and 2 for negative infinity.  You would only check the actual Val  
column if infinity was 0.

You would then write a method in your model that converts from your  
value to the two database columns.  Lookup up facade columns for one  
way to do this.

            - dan
-- 
Dan Kohn <mailto:dan@dankohn.com>
<http://www.dankohn.com/>  <tel:+1-415-233-1000>



On Jul 11, 2006, at 10:39 PM, Minkoo Seo wrote:
> Hi list.
>
> I''m writing a program that stores a lot of Floats into MySQL
database.
> Simplified version of the program use the following form of class.
>
> class Val < ActiveRecord::BASE
> end
>
> And Vals table contains one column:
>
> num double
>
> One of my data contains -Infinity for num and when I try to
> Val.new
> Val.num = <- Here goes -Inifinity
> Val.save!
>
> Then the program crashes:
> "/usr/local/stow/ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.3/ 
> lib/active_record/connection_adapters/abstract_adapter.rb:120:in
> `log'': Mysql::Error: Unknown column ''Infinity''
in ''field list'': INSERT
> INTO full_doc_indices (`etf`, `Id`, `phonemes`, `filename`,  
> `end_time`,
> `start_time`) VALUES(-Infinity, NULL, ''IH N T IH'',
''BN99EN_2'',
> 4952.77044, 4939.515) (ActiveRecord::StatementInvalid)"
>
> Obviously, ActiveRecord is using "-Infinity" literally, and then
MySQL
> treats "-Infinity" as column name as the message shows. How can I
> handle
> -Infinity then? I really have to store -Infinity anyway.
>
> Thanks.
>
> Sincerely,
> Minkoo Seo
>
> -- 
> Posted via http://www.ruby-forum.com/.
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> Rails mailing list
> Rails@lists.rubyonrails.org
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