How to migration in Rails

how-to-migration-in-rails.md

create

use rails gem

$ rails generate miogration [ClassName]

use bundle in rails gem

$ bundle exec rails generate migration [ClassName]

eg: ClassName -> AddColumnTitlesToUser

update

add cloumn to a table

$ rails generate migration AddTitleToUser title:string

remove column from a table

$ rails generate migration RemoveTitleToUser title:string

migration file

class AddTitleToUser < ActiveRecord::Migration[5.2]
  def change
    :
  end
end

def changeに対する記述

def change
  # カラムを追加
  add_column :table_name, :column_name, :type, options ...
  # カラム名を更新
  rename_column :table, :old_column, :new_column
end

migrationの実行

$ bundle exec rails db:migrate

How nice !
My first migration!

$ bundle exec rails generate migration AddLatestStatusTooXXX latest_status:integer