DatabaseMigrations

March 29th, 2013

ChangHoon Jeong(@seapy)ROR Lab.

- The 3th Round -ROR Lab. Season 3

13년 3월 30일 토요일

ROR Lab.

General Migration

• Use SQL(Database dependent)

• Run SQL by DB console

• Telling other developer and run SQL their local DB

• Run SQL when you deploy to production

13년 3월 30일 토요일

ROR Lab.

ROR Migration

• Use ruby code(Database independent)

• Run rake task

• Other developer run rake task(it’s rails convention)

• Run rake task when you deploy to production

13년 3월 30일 토요일

ROR Lab.

Migrations are Classes

class CreateProducts < ActiveRecord::Migration  def up    create_table :products do |t|      t.string :name      t.text :description       t.timestamps    end  end   def down    drop_table :products  endend

class CreateProducts < ActiveRecord::Migration  def change    create_table :products do |t|      t.string :name      t.text :description       t.timestamps    end  endend

rails 3.1 ~>

subclass of ActiveRecord::Migration

13년 3월 30일 토요일

ROR Lab.

Migration methods

• Database independent way

• Execute method allows you to execute arbitrary SQL

• Migrations are wrapped in a transaction(PostgreSQL or SQLite3, not support MySQL)

add_column

add_index

change_column

change_table

create_table

drop_table

remove_column

remove_index

rename_column

execute "SQL"

13년 3월 30일 토요일

ROR Lab.

Up & Down Methods (1)

class CreateProducts < ActiveRecord::Migration  def up    create_table :products do |t|      t.string :name      t.text :description       t.timestamps    end  end   def down    drop_table :products  endend

updated_at, created_at

13년 3월 30일 토요일

ROR Lab.

Up & Down Methods (2)

class AddReceiveNewsletterToUsers < ActiveRecord::Migration  def up    change_table :users do |t|      t.boolean :receive_newsletter, :default => false    end    User.update_all ["receive_newsletter = ?", true]  end   def down    remove_column :users, :receive_newsletter  endend

13년 3월 30일 토요일

ROR Lab.

Up & Down Methods (3)class ExampleMigration < ActiveRecord::Migration  def up    create_table :products do |t|      t.references :category    end    #add a foreign key    execute <<-SQL      ALTER TABLE products        ADD CONSTRAINT fk_products_categories        FOREIGN KEY (category_id)        REFERENCES categories(id)    SQL    add_column :users, :home_page_url, :string    rename_column :users, :email, :email_address  end   def down    rename_column :users, :email_address, :email    remove_column :users, :home_page_url    execute <<-SQL      ALTER TABLE products        DROP FOREIGN KEY fk_products_categories    SQL    drop_table :products  endend

category_id

13년 3월 30일 토요일

ROR Lab.

Up & Down Methods (3)class ExampleMigration < ActiveRecord::Migration  def up    create_table :products do |t|      t.references :category    end    #add a foreign key    execute <<-SQL      ALTER TABLE products        ADD CONSTRAINT fk_products_categories        FOREIGN KEY (category_id)        REFERENCES categories(id)    SQL    add_column :users, :home_page_url, :string    rename_column :users, :email, :email_address  end   def down    rename_column :users, :email_address, :email    remove_column :users, :home_page_url    execute <<-SQL      ALTER TABLE products        DROP FOREIGN KEY fk_products_categories    SQL    drop_table :products  endend

category_id

13년 3월 30일 토요일

ROR Lab.

class CreateProducts < ActiveRecord::Migration  def change    create_table :products do |t|      t.string :name      t.text :description       t.timestamps    end  endend

• create_table

• add_column

• add_index

• rename_table

• rename_column

• rename_index

• add_timestamps

• remove_timestamps

Change Method

13년 3월 30일 토요일

ROR Lab.

Supported Types

• not supported by Active Record

• t.column :name, 'typename'

:binary:boolean

:date:datetime:decimal

:float:integer

:primary_key:string:text:time

:timestamp

13년 3월 30일 토요일

ROR Lab.

• db/migrate directory

• YYYYMMDDHHMMSS_create_products.rb

• UTC timestamp

• The name of the migration class(CamelCased)

Migration Files Naming

13년 3월 30일 토요일

ROR Lab.

• $ rails generate model Post title:string

• $ rails generate scaffold Post title:string

• $ rails generate migration AddContentToPosts content:text

• $ rails generate migration RemoveContentFromPosts content:text

To CreateMigration Files

13년 3월 30일 토요일

ROR Lab.

Add & Remove Columns

• AddXXXToYYY

• RemoveXXXFromYYY

$ rails g migration AddNameToUsers

$ rails g migration RemoveNameFromUsers

13년 3월 30일 토요일

ROR Lab.

• $ rails destroy model Post title:string

• $ rails destroy scaffold Post title:string

• $ rails destroy migration AddContentToPosts content:text

To DestroyMigration Files

13년 3월 30일 토요일

ROR Lab.

Rake it~

• $ rake db:migrate

• $ rake db:rollback

• $ rake db:migrate:status

“up” state

“down” state

13년 3월 30일 토요일

ROR Lab.

Rake it~$ rake db:migrate:status mysql> select * from schema_migrations;

+----------------+| version |+----------------+| 20120531061820 || 20120531105534 || 20120531124444 || 20120531125446 || 20120531133035 || 20120601102629 || 20120603223525 || 20120603224330 || 20120603224625 || 20120604064155 || 20120604110743 || 20120702123904 || 20120702125358 || 20120703005951 || 20120704033651 || 20120728014210 || 20120728061841 || 20120728102213 || 20120729053924 || 20120804011723 || 20120804012821 || 20120804013538 || 20120808023400 || 20120810071351 |+----------------+34 rows in set (0.00 sec)

database: medibook_development

Status Migration ID Migration Name-------------------------------------------------- up 20120531061820 Create users up 20120531105534 Rolify create roles up 20120531124444 Create boards up 20120531125446 Create board types up 20120531133035 Create posts up 20120601102629 Create categories up 20120603223525 Create products up 20120603224330 Add some fields to users up 20120603224625 Add some fields to categories up 20120604064155 Add category id to products up 20120604110743 Add attachment product photo to products up 20120702123904 Add view count to products up 20120702125358 Create comments up 20120703005951 Create favourites up 20120704033651 Add account to users up 20120728014210 Add devise to users up 20120728061841 Remove password digest from users up 20120728102213 Create user groups up 20120729053924 Create users groups up 20120804011723 Add user details to users up 20120804012821 Create affiliations up 20120804013538 Add some fields to affiliations up 20120808023400 Add attachment company logo to affiliations up 20120810071351 Add active to users

13년 3월 30일 토요일

ROR Lab.

Rake it~$ rake db:version

$ cat db/schema.rb

ActiveRecord::Schema.define(:version => 20120831045454) do

create_table "ad_images", :force => true do |t| t.integer "adimageable_id" t.string "adimageable_type" t.integer "user_id" t.string "image_file_name" t.string "image_content_type" t.integer "image_file_size" t.datetime "created_at", :null => false t.datetime "updated_at", :null => false end

add_index "ad_images", ["adimageable_id"], :name => "index_ad_images_on_adimageable_id" add_index "ad_images", ["user_id"], :name => "index_ad_images_on_user_id"

Current version: 20120818023340

13년 3월 30일 토요일

ROR Lab.

Rake it~$ rake db:abort_if_pending_migrations

$ rake db:migrate:status

database: db/development.sqlite3

Status Migration ID Migration Name-------------------------------------------------- up 20120818022501 Create posts down 20120818023340 Create comments down 20120818031154 Create tags

$ rake db:abort_if_pending_migrations

You have 2 pending migrations: 20120818023340 CreateComments 20120818031154 CreateTagsRun `rake db:migrate` to update your database then try again.

13년 3월 30일 토요일

ROR Lab.

schema_migrations

• db/schema.rb

• A database table : history of migrations

$ rake db:migrate:status

• up• down

13년 3월 30일 토요일

ROR Lab.

Running Migrations

$ rake db:migrate

$ rake db:migrate VERSION=20090906120000

$ rake db:migrate:up VERSION=20090906120000

$ rake db:rollback

$ rake db:rollback STEP=3

UP

DOWN

db:schema:dump

db/schema.rb

13년 3월 30일 토요일

ROR Lab.

$ rake db:migrate

$ rake db:migrate VERSION=20120702125358

$ rake db:migrate:down VERSION=20120702125358

database: medibook_development

Status Migration ID -------------------------- up 20120531061820 up 20120531105534 up 20120531124444 up 20120531125446 up 20120531133035 up 20120601102629 up 20120603223525 up 20120603224330 up 20120603224625 up 20120604064155 up 20120604110743 up 20120702123904 up 20120702125358 up 20120703005951 up 20120704033651 up 20120728014210 up 20120728061841 up 20120728102213 up 20120729053924 up 20120804011723 up 20120804012821 up 20120804013538 up 20120808023400 up 20120810071351

Running Migrations

UP

db:migrate:down

13년 3월 30일 토요일

ROR Lab.

$ rake db:migrate

$ rake db:migrate VERSION=20120702125358

$ rake db:migrate:up VERSION=20120702125358

database: medibook_development

Status Migration ID -------------------------- up 20120531061820 up 20120531105534 up 20120531124444 up 20120531125446 up 20120531133035 up 20120601102629 up 20120603223525 down 20120603224330 down 20120603224625 down 20120604064155 down 20120604110743 down 20120702123904 down 20120702125358 down 20120703005951 down 20120704033651 down 20120728014210 down 20120728061841 down 20120728102213 down 20120729053924 down 20120804011723 down 20120804012821 down 20120804013538 down 20120808023400 down 20120810071351

Running Migrations

UP

db:migrate:up

13년 3월 30일 토요일

ROR Lab.

database: medibook_development

Status Migration ID -------------------------- up 20120531061820 up 20120531105534 up 20120531124444 up 20120531125446 up 20120531133035 up 20120601102629 up 20120603223525 up 20120603224330 up 20120603224625 up 20120604064155 up 20120604110743 up 20120702123904 up 20120702125358 up 20120703005951 up 20120704033651 up 20120728014210 up 20120728061841 up 20120728102213 up 20120729053924 up 20120804011723 up 20120804012821 up 20120804013538 up 20120808023400 up 20120810071351

$ rake db:rollback

$ rake db:migrate:redo

$ rake db:rollback STEP=3

$ rake db:migrate:redo STEP=3

Running Migrations

UP

13년 3월 30일 토요일

ROR Lab.

output of migrations• suppress_messages

• say

• indent option true/false

• say_with_time

• return integer, number of rows affected

13년 3월 30일 토요일

ROR Lab.

class CreateProducts < ActiveRecord::Migration

def change

suppress_messages do

create_table :products do |t|

t.string :name

end

end

say "Created a table"

suppress_messages {add_index :products, :name}

say "and an index!", true

say_with_time 'Waiting for a while' do

sleep 10

250

end

end

end

== CreateProducts: migrating ============

-- Created a table

-> and an index!

-- Waiting for a while

-> 10.0013s

-> 250 rows

== CreateProducts: migrated (10.0054s) ====

13년 3월 30일 토요일

ROR Lab.

# db/migrate/20100513121110_add_flag_to_product.rb class AddFlagToProduct < ActiveRecord::Migration  class Product < ActiveRecord::Base  end   def change    add_column :products, :flag, :integer    Product.reset_column_information    Product.all.each do |product|      product.update_attributes!(:flag => false)    end  endend

Model in Migration• YourTable.reset_column_information

• Alice and Bob’s Story

13년 3월 30일 토요일

ROR Lab.

App DB Init

$ rake db:reset

1. db:drop

2. db:setup

$ rake db:setup

1. db:create

2. db:schema:load

3. db:seed

using db/schema.rb

https://github.com/rails/rails/blob/master/activerecord/lib/active_record/railties/databases.rake

13년 3월 30일 토요일

ROR Lab.

Schema works

• $ rake db:schema:dump called by db:migrate create schema.rb

• $ rake db:schema:load load schema.rb

13년 3월 30일 토요일

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13년 3월 30일 토요일