Rails - Apr 2009 - create_table with unique combo

I need to create a table replacing default integer id with a string id
and making a combo of (id and version) unique primary key. Here is
what I''ve got so far.

class CreateCatalogs < ActiveRecord::Migration
  def self.up
    create_table :catalogs, :id => false do |t|
      t.string :id, :limit => 20, :null => false
      t.string :version, :default => ''01''

      t.timestamps
    end
  end

  def self.down
    drop_table :catalogs
  end
end

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hi slave,you can do it use the connection method of migration
use it like ActiveRecord::Base.connection_pool.checkout


2009/4/9 slava <slava_mikerin-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
>
> I need to create a table replacing default integer id with a string id
> and making a combo of (id and version) unique primary key. Here is
> what I''ve got so far.
>
> class CreateCatalogs < ActiveRecord::Migration
>  def self.up
>    create_table :catalogs, :id => false do |t|
>      t.string :id, :limit => 20, :null => false
>      t.string :version, :default => ''01''
>
>      t.timestamps
>    end
>  end
>
>  def self.down
>    drop_table :catalogs
>  end
> end
>
> >
>

-- 
明天会更好

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alternatively if i leave default integer id as primary key I need to
make sure combo of name and version are unique.

    create_table :catalogs do |t|
      t.string :name
      t.string :version, :default => ''01''
      t.timestamps
    end
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On Thu, Apr 9, 2009 at 6:56 AM, slava
<slava_mikerin-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
wrote:
>
>
> alternatively if i leave default integer id as primary key I need to
> make sure combo of name and version are unique.
>
>    create_table :catalogs do |t|
>      t.string :name
>      t.string :version, :default => ''01''
>      t.timestamps
>    end
> >
>
To ensure uniqueness, you can add an index

add_index :catalogs, [:name, :version], :unique => true

Andrew Timberlake
http://ramblingsonrails.com
http://www.linkedin.com/in/andrewtimberlake

"I have never let my schooling interfere with my education" - Mark
Twain

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on the same subject..
I need to ensure uniqness of name in a table. I tried setting collumn
to unique (see below) but that did not work. I still can create
records with same name field.

   create_table :properties do |t|
      t.string :name, :unique => true
      t.string :description

      t.timestamps
    end
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