From: Robert Klemme <shortcutter@...>
Date: 2009-11-22T23:55:06+09:00
Subject: Re: Pseudo array for Rails migration

On 22.11.2009 15:06, Ralph Shnelvar wrote:
> Consider
> 
> 
> N_X = 20 # size of pseudo array
> 
> class CreatePeople < ActiveRecord::Migration
> 
>     create_table :people do |t|
>       t.string  :first_name             , :null => false
>       .
>       .
>       .
>       t.integer :x00
>       t.integer :x01
>       t.integer :x02
>       .
>       .
>       .
>       t.integer :x18
>       t.integer :x19
> 
> 
>       t.timestamps
>     end
> end
> 
> 
> 
> What is the (best) way of generating the "t.integer :xYY" (where YY is
> 00 through 19, inclusive) which is dependent on N_X.

What stops you from doing

N_X = 20 # size of pseudo array

class CreatePeople < ActiveRecord::Migration

     create_table :people do |t|
       t.string  :first_name             , :null => false
       .
       .
       .
       N_X.times do |i|
         t.integer(("x%02d" % i).to_sym)
       end

       t.timestamps
     end
end

?  Btw, having columns with indexes in their name is considered bad 
schema design because you either could normalize it into another table 
and join or provide more meaningful names instead of "x02" if it is used 
as a placeholder.  My 0.02EUR.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
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