refresher - A simble database schema cache refresh
Tl;dr
Refresher allows you to create user and database with just only single
command: rake db_refresher. Then you can continue with rake db:migrate
Installation and Usage
Add into your Gemfile:
gem 'refresher'
Then run
rake db_refresher; rake db:migrate
You may want to run db:seeds too if you have any.
Story
Imagine you are prototyping a Rails application with much table (let say 30+ tables) at the first time. You might end up with this:
20151210051128_create_orders.rb
20151210113138_add_payment_commit_time_to_orders.rb
20151213090513_remove_payment_hash_from_order.rb
20151214042001_add_payment_to_order.rb
20151214051032_create_payments.rb
There might be so much add and remove migration file. In fact, you
are prototyping so database schema is expected to change in this early
stage. Also, there is no single overview about current schema in migration
files. You might need to see db/schema.rb or use model annotation tools
like annotate to get a summary of current schema/table.
When prototyping, you might want to see everything about a table
in a single migration file. You might only want create_orders.rb in contrast
of four migration files describing a single table. Unfortunately, you can't
simply add field to create_orders then run rake db:migrate
because Rails won't notice the different of migration file if
the migration timestamp id has been existed in db. You must db:rollback
and then db:migrate again, for every single migration you change (but
has been persisted to db).
Another way is to just drop the entire db, then create the db again, then run the migration (rake db:drop db:create db:migrate). That is okay if you are prototyping 10 tables, but imagine you are prototyping with 60 tables, and you only want to change last 5 tables, it might take 20+ seconds just to drop and populate 60 tables. In this case, perhaps rollback is better.
With refresher, you can populate db with SQL cache, so let say your latest checkpoint for you is migration id 2015, and you change 2016
2014_create_a
2015_create_b <-- latest schema in cache
2016_create_c
2017_create_d
refresher With Cache
rake db:refresh
rake db:refresh_invalidate_cache
rake db:refresh_persist_cache