Difference between rake db:migrate db:reset and db:schema:load

up vote266down votefavorite 241

The difference between rake db:migrate and rake db:reset is pretty clear in my head. The thing which I don't understand is how rake db:schema:load different from the former two. Just to be sure that I am on the same page: rake db:migrate - Runs the migrations which haven't been run yet. rake db:reset - Clears the database (presumably does a rake db:drop + rake db:create + rake db:migrate) and runs migration on a fresh database. Please help to clarify, if my understanding has gone wrong. ruby-on-rails ruby database rake shareimprove this question edited Jun 17 '14 at 7:58 ekremkaraca 1,17911029 asked Apr 24 '12 at 16:11 Gaurav Agarwal 4,75741227

2   Does rake --tasks help ? – zx1986 Nov 28 '14 at 2:42 add a comment

4 Answers

activeoldestvotes

up vote654down voteaccepted

db:migrate runs (single) migrations that have not run yet. db:create creates the database db:drop deletes the database db:schema:load creates tables and columns within the (existing) database following schema.rb db:setup does db:create, db:schema:load, db:seed db:reset does db:drop, db:setup Typically, you would use db:migrate after having made changes to the schema via new migration files (this makes sense only if there is already data in the database). db:schema:load is used when you setup a new instance of your app. I hope that helps. UPDATE for rails 3.2.12: I just checked the source and the dependencies are like this now: db:create creates the database for the current env db:create:all creates the databases for all envs db:drop drops the database for the current env db:drop:all drops the databases for all envs db:migrate runs migrations for the current env that have not run yet db:migrate:up runs one specific migration db:migrate:down rolls back one specific migration db:migrate:status shows current migration status db:rollback rolls back the last migration db:forward advances the current schema version to the next one db:seed (only) runs the db/seed.rb file db:schema:load loads the schema into the current env's database db:schema:dump dumps the current env's schema (and seems to create the db as well) db:setup runs db:schema:load, db:seed db:reset runs db:drop db:setup db:migrate:redo runs (db:migrate:down db:migrate:up) or (db:rollback db:migrate) depending on the specified migration db:migrate:reset runs db:drop db:create db:migrate For further information please have a look athttps://github.com/rails/rails/blob/v3.2.12/activerecord/lib/active_record/railties/databases.rake (for Rails 3.2.x) andhttps://github.com/rails/rails/blob/v4.0.5/activerecord/lib/active_record/railties/databases.rake (for Rails 4.0.x) shareimprove this answer edited 2 days ago jiroch 55 answered Apr 24 '12 at 16:48 moritz 13.7k22131

10   Here is the file with answers :) - github.com/rails/rails/blob/master/activerecord/lib/… – cutalion Apr 24 '12 at 16:54 3   @cutation: db:setup does surely not run db:migrate, because it would be much too brittle to run all migrations just for a db setup (this is what schema.rb is for). – moritz Apr 25 '12 at 9:10 2   I'm executing db:reset and it's seeding my db. Why could it be? – Alejandro Riedel Feb 11 '13 at 0:17 1   @AlejandroRiedel: Please have a look at the update. – moritz Feb 20 '13 at 13:09 @moritz: it makes sense now. Thanks for the heads up. – Alejandro Riedel Feb 22 '13 at 2:44 show 5 more comments

up vote1down vote	As far as I understand, it is going to drop your database and re-create it based on your db/schema.rbfile. That is why you need to make sure that your schema.rb file is always up to date and under version control. shareimprove this answer answered Apr 24 '12 at 16:25 Simon Bagreev 1,9371220
	add a comment

up vote0down vote	You may find all the db do stuff in this file on github these days. https://github.com/rails/rails/blob/4-2-stable/railties/lib/rails/tasks/engine.rake If you really want to have some SQL fun try doing a structure dump. shareimprove this answer answered Feb 7 at 18:20 Douglas G. Allen 623313
	add a comment

up vote-1down vote	Thanks for valuable post. As I found from this discussion there is only one way to recreate DB from migrations sequence i.e. NOT form db/schema.rb. This way is the following: rake db:drop && rake db:create && rake db:migrate && rake db:seed shareimprove this answer answered Sep 3 at 13:58 SashaEgorov 718813
	Precisely. Not sure why its posted as an Answer, instead of a comment! – Gaurav Agarwal Sep 4 at 9:00 1   Or even shorter - rake db:drop db:create db:migrate db:seed – Anton Antonov Sep 14 at 16:31 add a comment

Your Answer