Ruby on Rails - sqlite 3 rake migrations not updating the database - ruby-on-rails

Question

I am using RoR (3.2.2) and SQLite 3 (1.3.5). When I initially generate a model I am able to successfully create a database. However, whenever I try to use the migration generator it appears to not have any issues in the command line (no errors), but when I check the database nothing has updated or changed.
For example, I create this database:
$ rails generate model User name:string email:string
db/migrate/[timestamp]_create_users.rb
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name
t.string :email
t.timestamps
end
end
end
And I run a migration:
$ bundle exec rake db:migrate
So far so good, I check my database using SQLite Database Browser and everything looks as it should.
Then if I want to add an index:
$ rails generate migration add_index_to_users_email
db/migrate/[timestamp]_add_index_to_users_email.rb
class AddIndexToUsersEmail < ActiveRecord::Migration
def change
add_index :users, :email, unique: true
end
end
I run a migration:
$ bundle exec rake db:migrate
And command line gives me the following:
bundle exec rake db:migrate
== AddIndexToUsersEmail: migrating ===========================================
== AddIndexToUsersEmail: migrated (0.0000s) ==================================
However, when I check my database using SQLite Database Browser it isn't updated. I get the same results if I try to add new columns to the table, etc. The only way I have been able to do migrations is manually updating the database using the SQLite Database Browser. Any help as to why it is not working through Rails and the command line would be greatly appreciated.
Here is my gemfile:
source 'https://rubygems.org'
gem 'rails', '3.2.2'
gem 'bootstrap-sass', '2.0.0'
group :development, :test do
gem 'sqlite3', '1.3.5'
gem 'rspec-rails', '2.8.1'
gem 'annotate', '~> 2.4.1.beta'
end
group :assets do
gem 'sass-rails', '3.2.4'
gem 'coffee-rails', '3.2.2'
gem 'uglifier', '1.2.3'
end
gem 'jquery-rails', '2.0.0'
group :test do
gem 'capybara', '1.1.2'
end
group :production do
gem 'pg', '0.12.2'
end
Database.yml
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
production:
adapter: sqlite3
database: db/production.sqlite3
pool: 5
timeout: 5000
Example of successfully adding a column:
rails generate migration add_password_digest_to_users password_digest:string
invoke active_record
create db/migrate/20120318235656_add_password_digest_to_users.rb
$ subl db/migrate/[timestamp]_add_password_digest_to_users.rb
$ bundle exec rake db:migrate
== AddPasswordDigestToUsers: migrating =======================================
-- add_column(:users, :password_digest, :string) -> 0.0008s
== AddPasswordDigestToUsers: migrated (0.0009s) ==============================
Example of unsuccessfully adding a column:
$ rails generate migration add_remember_token_to_users
invoke active_record
create db/migrate/20120319010623_add_remember_token_to_users.rb
$ subl db/migrate/[timestamp]_add_remember_token_to_users.rb
$ bundle exec rake db:migrate
== AddRememberTokenToUsers: migrating ========================================
== AddRememberTokenToUsers: migrated (0.0000s) ===============================
Notice when it fails to update the database the migration time is zero. I'm not sure what I am doing wrong. Thanks in advance for any suggestions.

Answer 1

I solved the problem undoing the last migration with
rails destroy migration add_index_to_users_email
Then I closed my terminals to ensure that all db connections were closed, then I run
rake db:reset
Finally, running the same commands again
rails generate migration add_index_to_users_email
Updating the file with the same content and running
rake db:migrate
All the same commands and files that were not working before now worked at all (for me).
I hope this works for you as well.

Answer 2

I think what happens is you get the syntax slightly wrong (it's insanely tricky) then you get an empty migration which doesn't do anything.
I would double check that the actual migration file has add column. I often end up manually putting the actual change (or up/down) in.
As t Harrison says, adding an index is more subtle - as you sure it doesn't get added if you refresh the sqlite borwser. The examples you gave that worked... are to add columns...

Answer 3

The output you posted from the add index example shows that the migration is indeed running ... but you report it's not actually doing anything. Try bundle exec rake:db rollback (with optional STEP=n to go more than one step back). This really should "just work", and a case of an index might be a little subtle -- try adding a column or something (which you said you have done, but, just to be sure). Does it really not work? How can you tell?