1. ROR Lab. Season 3
- The 3th Round -
Database
Migrations
March 29th, 2013
ChangHoon Jeong(@seapy)
ROR Lab.
13년 3월 30일 토요일

2. 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
ROR Lab.
13년 3월 30일 토요일

3. 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
ROR Lab.
13년 3월 30일 토요일

4. Migrations are Classes
rails 3.1 ~>
class CreateProducts < ActiveRecord::Migration class CreateProducts < ActiveRecord::Migration
def up def change
create_table :products do |t| create_table :products do |t|
t.string :name t.string :name
t.text :description t.text :description
t.timestamps t.timestamps
end end
end end
end
def down
drop_table :products
end
end
subclass of ActiveRecord::Migration
ROR Lab.
13년 3월 30일 토요일

5. Migration methods
add_column
add_index
• Database independent way change_column
• Execute method allows you to change_table
create_table
execute arbitrary SQL
drop_table
• Migrations are wrapped in a remove_column
transaction(PostgreSQL or remove_index
SQLite3, not support MySQL) rename_column
execute "SQL"
ROR Lab.
13년 3월 30일 토요일

6. 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 updated_at, created_at
def down
drop_table :products
end
end
ROR Lab.
13년 3월 30일 토요일

7. 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
end
end
ROR Lab.
13년 3월 30일 토요일

8. 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
category_id
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
end
end
ROR Lab.
13년 3월 30일 토요일

9. 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
category_id
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
end
end
ROR Lab.
13년 3월 30일 토요일

10. Change Method
class CreateProducts < ActiveRecord::Migration
def change
create_table :products do |t|
t.string :name • create_table
t.text :description • add_column
• add_index
t.timestamps • rename_table
end • rename_column
end • rename_index
end
• add_timestamps
• remove_timestamps
ROR Lab.
13년 3월 30일 토요일

11. Supported Types
:binary
:boolean
:date
:datetime
:decimal
:float
• not supported by Active Record
:integer
:primary_key
• t.column :name, 'typename'
:string
:text
:time
:timestamp
ROR Lab.
13년 3월 30일 토요일

12. Migration Files Naming
• db/migrate directory
• YYYYMMDDHHMMSS_create_products.rb
• UTC timestamp
• The name of the migration
class(CamelCased)
ROR Lab.
13년 3월 30일 토요일

13. To Create
Migration Files
• $ rails generate model Post title:string
• $ rails generate scaffold Post title:string
• $ rails generate migration
AddContentToPosts content:text
• $ rails generate migration
RemoveContentFromPosts content:text
ROR Lab.
13년 3월 30일 토요일

14. Add & Remove
Columns
• AddXXXToYYY
• RemoveXXXFromYYY
$ rails g migration AddNameToUsers
$ rails g migration RemoveNameFromUsers
ROR Lab.
13년 3월 30일 토요일

15. To Destroy
Migration Files
• $ rails destroy model Post title:string
• $ rails destroy scaffold Post title:string
• $ rails destroy migration
AddContentToPosts content:text
ROR Lab.
13년 3월 30일 토요일

16. Rake it~
• $ rake db:migrate “up” state
• $ rake db:rollback “down” state
• $ rake db:migrate:status
ROR Lab.
13년 3월 30일 토요일

17. Rake it~
$ rake db:migrate:status mysql> select * from schema_migrations;
+----------------+
| version |
database: medibook_development +----------------+
| 20120531061820 |
Status Migration ID Migration Name | 20120531105534 |
| 20120531124444 |
-------------------------------------------------- | 20120531125446 |
up 20120531061820 Create users | 20120531133035 |
up 20120531105534 Rolify create roles | 20120601102629 |
up 20120531124444 Create boards | 20120603223525 |
up 20120531125446 Create board types | 20120603224330 |
up 20120531133035 Create posts | 20120603224625 |
up 20120601102629 Create categories | 20120604064155 |
| 20120604110743 |
up 20120603223525 Create products | 20120702123904 |
up 20120603224330 Add some fields to users | 20120702125358 |
up 20120603224625 Add some fields to categories | 20120703005951 |
up 20120604064155 Add category id to products | 20120704033651 |
up 20120604110743 Add attachment product photo to products | 20120728014210 |
up 20120702123904 Add view count to products | 20120728061841 |
up 20120702125358 Create comments | 20120728102213 |
| 20120729053924 |
up 20120703005951 Create favourites | 20120804011723 |
up 20120704033651 Add account to users | 20120804012821 |
up 20120728014210 Add devise to users | 20120804013538 |
up 20120728061841 Remove password digest from users | 20120808023400 |
up 20120728102213 Create user groups | 20120810071351 |
up 20120729053924 Create users groups +----------------+
up 20120804011723 Add user details to users 34 rows in set (0.00 sec)
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
ROR Lab.
13년 3월 30일 토요일

18. Rake it~
$ rake db:version
Current version: 20120818023340
$ 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"
ROR Lab.
13년 3월 30일 토요일

19. Rake it~
$ rake db:abort_if_pending_migrations
$ rake db:migrate:status $ rake db:abort_if_pending_migrations
database: db/development.sqlite3 You have 2 pending migrations:
20120818023340 CreateComments
Status Migration ID Migration Name 20120818031154 CreateTags
-------------------------------------------------- Run `rake db:migrate` to update your database then
up 20120818022501 Create posts try again.
down 20120818023340 Create comments
down 20120818031154 Create tags
ROR Lab.
13년 3월 30일 토요일

20. schema_migrations
• db/schema.rb
• A database table : history of migrations
$ rake db:migrate:status
• up
• down
ROR Lab.
13년 3월 30일 토요일

21. Running Migrations
db/schema.rb
db:schema:dump
UP
$ rake db:migrate
$ rake db:migrate VERSION=20090906120000
$ rake db:migrate:up VERSION=20090906120000
DOWN
$ rake db:rollback
$ rake db:rollback STEP=3
ROR Lab.
13년 3월 30일 토요일

22. Running Migrations
database: medibook_development
Status Migration ID
--------------------------
UP
up 20120531061820
up 20120531105534
up 20120531124444
up 20120531125446
$ rake db:migrate up 20120531133035
up 20120601102629
$ rake db:migrate VERSION=20120702125358 up 20120603223525
up 20120603224330
$ rake db:migrate:down VERSION=20120702125358 up 20120603224625
up 20120604064155
up 20120604110743
up 20120702123904
up 20120702125358
up 20120703005951
up 20120704033651
up 20120728014210
up 20120728061841
up 20120728102213
up 20120729053924
up 20120804011723
db:migrate:down
up 20120804012821
up 20120804013538
up 20120808023400
up 20120810071351
ROR Lab.
13년 3월 30일 토요일

23. Running Migrations
database: medibook_development
Status Migration ID
--------------------------
UP
up 20120531061820
up 20120531105534
up 20120531124444
up 20120531125446
$ rake db:migrate up 20120531133035
up 20120601102629
$ rake db:migrate VERSION=20120702125358 up 20120603223525
down 20120603224330
$ rake db:migrate:up VERSION=20120702125358 down 20120603224625
down 20120604064155
down 20120604110743
down 20120702123904
down 20120702125358
down 20120703005951
down 20120704033651
down 20120728014210
down 20120728061841
down 20120728102213
down 20120729053924
down 20120804011723
db:migrate:up
down 20120804012821
down 20120804013538
down 20120808023400
down 20120810071351
ROR Lab.
13년 3월 30일 토요일

24. Running Migrations
database: medibook_development
Status Migration ID
--------------------------
UP
up 20120531061820
up 20120531105534
$ rake db:rollback up 20120531124444
up 20120531125446
$ rake db:migrate:redo up 20120531133035
up 20120601102629
$ rake db:rollback STEP=3 up 20120603223525
up 20120603224330
$ rake db:migrate:redo STEP=3 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
ROR Lab.
13년 3월 30일 토요일

25. output of migrations
• suppress_messages
• say
• indent option true/false
• say_with_time
• return integer, number of rows affected
ROR Lab.
13년 3월 30일 토요일

26. 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 == CreateProducts: migrating ============
end -- Created a table
end -> and an index!
-- Waiting for a while
-> 10.0013s
-> 250 rows
== CreateProducts: migrated (10.0054s) ====
ROR Lab.
13년 3월 30일 토요일

27. Model in Migration
• YourTable.reset_column_information
# 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
end
end
• Alice and Bob’s Story
ROR Lab.
13년 3월 30일 토요일

28. App DB Init
using db/schema.rb
$ rake db:setup $ rake db:reset
1. db:create 1. db:drop
2. db:schema:load 2. db:setup
3. db:seed
https://github.com/rails/rails/blob/master/activerecord/lib/active_record/railties/databases.rake
ROR Lab.
13년 3월 30일 토요일

29. Schema works
• $ rake db:schema:dump
called by db:migrate
create schema.rb
• $ rake db:schema:load
load schema.rb
ROR Lab.
13년 3월 30일 토요일

30. 감사합니다.

31.
13년 3월 30일 토요일