Purge or recreate a Ruby on Rails database
Ruby on-RailsRuby on-Rails-3RakeRuby on-Rails Problem Overview
I have a dev Ruby on Rails database full of data. I want to delete everything and rebuild the database. I'm thinking of using something like:
rake db:recreate
Is this possible?
Ruby on-Rails Solutions
Solution 1 - Ruby on-Rails
I know two ways to do this:
This will reset your database and reload your current schema with all:
rake db:reset db:migrate
This will destroy your db and then create it and then migrate your current schema:
rake db:drop db:create db:migrate
All data will be lost in both scenarios.
Solution 2 - Ruby on-Rails
On Rails 4, all needed is
$ rake db:schema:load
That would delete the entire contents on your DB and recreate the schema from your schema.rb file, without having to apply all migrations one by one.
Solution 3 - Ruby on-Rails
I use the following one liner in Terminal.
$ rake db:drop && rake db:create && rake db:migrate && rake db:schema:dump && rake db:test:prepare
I put this as a shell alias and named it remigrate
By now, you can easily "chain" Rails tasks:
$ rake db:drop db:create db:migrate db:schema:dump db:test:prepare # db:test:prepare no longer available since Rails 4.1.0.rc1+
Solution 4 - Ruby on-Rails
Update: In Rails 5, this command will be accessible through this command:
rails db:purge db:create db:migrate RAILS_ENV=test
As of the newest rails 4.2 release you can now run:
rake db:purge
Source: commit
# desc "Empty the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (use db:drop:all to drop all databases in the config). Without RAILS_ENV it defaults to purging the development and test databases."
task :purge => [:load_config] do
ActiveRecord::Tasks::DatabaseTasks.purge_current
end
It can be used together like mentioned above:
rake db:purge db:create db:migrate RAILS_ENV=test
Solution 5 - Ruby on-Rails
Depending on what you're wanting, you can use…
rake db:create
…to build the database from scratch from config/database.yml
, or…
rake db:schema:load
…to build the database from scratch from your schema.rb
file.
Solution 6 - Ruby on-Rails
From the command line run
rake db:migrate:reset
Solution 7 - Ruby on-Rails
Use like
rake db:drop db:create db:migrate db:seed
All in one line. This is faster since the environment doesn't get reloaded again and again.
db:drop - will drop database.
db:create - will create database (host/db/password will be taken from config/database.yml)
db:migrate - will run existing migrations from directory (db/migration/.rb)*.
db:seed - will run seed data possible from directory (db/migration/seed.rb)..
I usually prefer:
rake db:reset
to do all at once.
Cheers!
Solution 8 - Ruby on-Rails
In Rails 6 there is a convenient way for resetting DB and planting seeds again:
rails db:seed:replant # Truncates tables of each database for current environment and loads the seeds
Solution 9 - Ruby on-Rails
Just issue the sequence of the steps: drop the database, then re-create it again, migrate data, and if you have seeds, sow the database:
rake db:drop db:create db:migrate db:seed
Since the default environment for rake
is development, in case if you see the exception in spec tests, you should re-create db for the test environment as follows:
RAILS_ENV=test rake db:drop db:create db:migrate
In most cases the test database is being sowed during the test procedures, so db:seed
task action isn't required to be passed. Otherwise, you shall to prepare the database:
rake db:test:prepare
or
RAILS_ENV=test rake db:seed
Additionally, to use the recreate task you can add into Rakefile the following code:
namespace :db do
task :recreate => [ :drop, :create, :migrate ] do
if ENV[ 'RAILS_ENV' ] !~ /test|cucumber/
Rake::Task[ 'db:seed' ].invoke
end
end
end
Then issue:
rake db:recreate
Solution 10 - Ruby on-Rails
You can manually do:
rake db:drop
rake db:create
rake db:migrate
Or just rake db:reset
, which will run the above steps but will also run your db/seeds.rb
file.
An added nuance is that rake db:reset
loads directly from your schema.rb
file as opposed to running all the migrations files again.
You data gets blown away in all cases.
Solution 11 - Ruby on-Rails
You can use this following command line:
rake db:drop db:create db:migrate db:seed db:test:clone
Solution 12 - Ruby on-Rails
To drop a particular database, you can do this on rails console:
$rails console
Loading development environment
1.9.3 > ActiveRecord::Migration.drop_table(:<table_name>)
1.9.3 > exit
And then migrate DB again
$bundle exec rake db:migrate
Solution 13 - Ruby on-Rails
On rails 4.2, to remove all data but preserve the database
$ bin/rake db:purge && bin/rake db:schema:load
https://github.com/rails/rails/blob/4-2-stable/activerecord/CHANGELOG.md
Solution 14 - Ruby on-Rails
You can use
db:reset
- for run db:drop and db:setup or
db:migrate:reset
- which runs db:drop, db:create and db:migrate.
dependent at you want to use exist schema.rb
Solution 15 - Ruby on-Rails
According to Rails guide, this one liner should be used because it would load from the schema.rb
instead of reloading the migration files one by one:
rake db:reset
Solution 16 - Ruby on-Rails
Because in development , you will always want to recreate the database,you can define a rake task in your lib/tasks folder like that.
namespace :db do
task :all => [:environment, :drop, :create, :migrate] do
end
end
and in terminal you will run
rake db:all
it will rebuild your database
Solution 17 - Ruby on-Rails
I think the best way to run this command:
**rake db:reset** it does db:drop, db:setup
rake db:setup does db:create, db:schema:load, db:seed
Solution 18 - Ruby on-Rails
Simply you can run
rake db:setup
It will drop database, create new database and populate db from seed if you created seed file with some data.
Solution 19 - Ruby on-Rails
3 options, same result:
1. All steps:
$ rake db:drop # deletes the database for the current env
$ rake db:create # creates the database for the current env
$ rake db:schema:load # loads the schema already generated from schema.rb / erases data
$ rake db:seed # seed with initial data
2. Reset:
$ rake db:reset # drop / schema:load / seed
3. Migrate:reset:
$ rake db:migrate:reset # drop / create / migrate
$ rake db:seed
Notes:
- If schema:load is used is faster than doing all migrations, but same result.
- All data will be lost.
- You can run multiple rakes in one line.
- Works with rails 3.
Solution 20 - Ruby on-Rails
I've today made quite a few changes to my rails schema. I realised I needed an additional two models in a hierarchy and some others to be deleted. There were many little changes required to the models and controllers.
I added the two new models and created them, using:
rake db:migrate
Then I edited the schema.rb file. I manually removed the old models that were no longer required, changed the foreign key field as required and just reordered it a bit to make it clearer to me. I deleted all the migrations, and then re-ran the build via:
rake db:reset
It worked perfectly. All the data has to be reloaded, of course. Rails realised the migrations had been deleted and reset the high-water mark:
-- assume_migrated_upto_version(20121026094813, ["/Users/sean/rails/f4/db/migrate"])
Solution 21 - Ruby on-Rails
I use:
rails db:drop
to delete the databases.rails db:create
to create the databases based onconfig/database.yml
The previous commands may be replaced with rails db:reset
.
Don't forget to run rails db:migrate
to run the migrations.