Rails - Jul 2006 - Regenerate DB

Hi again :),

I''m playing with migrations. I''ve created some migrations
classes and
with
rake db:migrate the tables are created and altered fine, but then I 
dropped
some of the tables and when I run db:migrate command again I don''t get 
tables
being re-created.

What am I doing wrong? Is there a way to run db:migration in order to 
drop the
tables?

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

On 7/13/06, Eduardo Y??ez Parareda <eduardo.yanez@gmail.com>
wrote:
> Hi again :),
>
> I''m playing with migrations. I''ve created some migrations
classes and
> with
> rake db:migrate the tables are created and altered fine, but then I
> dropped
> some of the tables and when I run db:migrate command again I don''t
get
> tables
> being re-created.
>
> What am I doing wrong? Is there a way to run db:migration in order to
> drop the
> tables?
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
Rails uses the schema_info table to determine what migrations to run.
When you drop a table via the command line, it doesn''t update the
schema_info table.  The proper way is to run migrate with the version
option.  For example if you had

class CreateUsers < ActiveRecord::Migration
  def self.up
    create_table :users do |t|
      t.column :username, :string, :default => "", :null =>
false
      t.column :password_salt, :string
      t.column :password_hash, :string
      t.column :email, :string
    end
  end

  def self.down
    drop_table :users
  end
end

And that was in 006_create_user.rb, then you would do
rake db:migrate VERSION=5

to migrate to the version below this one.  It would call the down
method, which drops the users table.

Run rake db:migrate --help to see all the options.
http://wiki.rubyonrails.com/rails/pages/UsingMigrations has a lot of
very useful information as well.

Pat

I would try:

rake db:migrate VERSION=1

then

rake db:migrate VERSION=X   <- X is your last version

> -----Original Message-----
> From: rails-bounces@lists.rubyonrails.org [mailto:rails-
> bounces@lists.rubyonrails.org] On Behalf Of Eduardo Y??ez Parareda
> Sent: Thursday, July 13, 2006 10:11 AM
> To: rails@lists.rubyonrails.org
> Subject: [Rails] Regenerate DB
> 
> Hi again :),
> 
> I''m playing with migrations. I''ve created some migrations
classes and
> with
> rake db:migrate the tables are created and altered fine, but then I
> dropped
> some of the tables and when I run db:migrate command again I don''t
get
> tables
> being re-created.
> 
> What am I doing wrong? Is there a way to run db:migration in order to
> drop the
> tables?
I messed my tables up pretty good and found that rake migrate VERSION=0 dropped
all tables in the database.  Rake migrate then created new ones to the latest
level.  Be very careful if you have data you would like to preserve.

Regards,
Rich

Or add this to your Rakefile:

namespace :db do
  desc "Revert database schema back to version 0, then up to the current
version."
  task :reload => :environment do
    # migrate back to the stone age
    ENV[''VERSION''] = ''0''
    Rake::Task["db:migrate"].execute

    # forward, comrades, to the future!
    ENV.delete(''VERSION'')
    Rake::Task["db:migrate"].execute

    # finally, load up the fixtures
    Rake::Task["db:fixtures:load"].invoke
  end
end

(snipped of technoweenie)

On 7/13/06, Roland Mai <roland.mai@gmail.com>
wrote:
>
> I would try:
>
> rake db:migrate VERSION=1
>
> then
>
> rake db:migrate VERSION=X   <- X is your last version
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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