rails の migration の仕様について rails Active Record MigrationFile () Migration File file name alphabetical order ( file name datetime prefix ) 1. MigrationFile () 2. db:setup schema.rb MigrationFile db/migrations rails migration # * rails `db:migrate`, `db:reset`, `db:setup`, `db:migrate:reset` ? * ?

schema_migration
(YYYYMMDDHHMMSS)
db/migrate



1. MigrationFile ()

DB

2. MigrationFile db/migrations





> db:migrate, db:reset, db:setup, db:migrate:reset ?

schema.rb


**db:migrate**
DB


**db:migrate:reset**



schema.rb

**db:reset**
schema.rb
schema.rb

**db:setup**


DB

schema.rb



setup db:migrate

* * *

<

db:migrate:reset = db:drop + db:migrate
db:reset = db:drop + db:setup
db:setup = db:create + db:schema:load + db:seed


<
db:schema:load force:true drop and create
create already exist

db:migrate