- 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:migrate: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:migrate:rollback db:migrate:migrate) depending on the specified migration
- db:migrate:reset runs db:drop db:create db:migrate
http://stackoverflow.com/questions/10301794/difference-between-rake-dbmigrate-dbreset-and-dbschemaload
