scenic-cascade
is a scenic migration file generator that supports cascading view updates.
Add this line to your application's Gemfile:
gem 'scenic-cascade'
And then execute:
$ bundle install
Or install it yourself as:
$ gem install scenic-cascade
To generate migration files, use scenic:view:cascade
generator instead of scenic:view
.
The following example generates migration files for search_results
view.
$ bin/rails generate scenic:view:cascade search_results
create db/views/search_results_v01.sql
create db/migrate/20220714233704_create_search_results.rb
Consider a situation where the following three views exist:
first_results
is a parent view (version 1)second_results
is a materialized view that depends onfirst_results
(version 3)third_results
is a view that depends onfirst_results
andsecond_results
(version 2)
-- first_results
SELECT 'foo' AS bar;
-- second_results
SELECT * FROM first_results;
-- third_results
SELECT * FROM first_results UNION SELECT * FROM second_results;
Executing the scenic:view:cascade
generator for first_results
in this state will generate the following migration file:
$ bin/rails generate scenic:view:cascade first_results
create db/views/first_results_v02.sql
create db/migrate/20220714233704_update_first_results_to_version_2.rb
Since all dependencies are described, you can execute bin/rails db:migrate
without changing the migration file.
Warning
Currently, index re-creation is not supported.
Please change a migration file to recreate indexes if it contains drop_view
for materialized views.
class UpdateSearchResultsToVersion2 < ActiveRecord::Migration
def change
drop_view :third_results, revert_to_version: 2, materialized: false
drop_view :second_results, revert_to_version: 3, materialized: true
replace_view :first_results, version: 2, revert_to_version: 1
create_view :second_results, version: 3, materialized: true
create_view :third_results, version: 2, materialized: false
end
end
After checking out the repo, run bin/setup
to install dependencies. Then, run rake spec
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and the created tag, and push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/akiomik/scenic-cascade. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.
Everyone interacting in the `scenic-cascade' project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.