1. Architecture Rails:
Controllers: Rails look to find controllers classes. A controllers handles a web request from user.
Views: Holds the display templates to fill in with data from our application, convert to HTML, and
return to the user's browser.
Models: Holds the classes that model and wrap the data stored in our application's database.
Helpers: Holds any helper classes used to assist the model, view, and controllers classes
Methods:
link_to → creates a hyperlink to an action
example: <%= link_to "Hello", say_hello_path %>
Marshaling Objects: Take an object and convert it into a stream of bytes that can be stored outside the
app.
rails generate migration add_columnname_to_tablename columnname:datatype
example: rails generate migration add_password_to_users password:string
Problem Solve Take-note
Get URL parameter path = request.fullpath
path_search = URI.parse(path)
parse_url = CGI.parse(path_search.query)
array_facility_choose = parse_url['search[facilities][]']#params['search']['facilities']
name_facility = Array.new # content all name of facility choose
search[prefecture]=&search[departments][]=3&search[facilities][]=2
To create a model
that references
another, use the
rails model
generator:
$ rails g model wheel car:references
class Wheel < ActiveRecord::Base
belongs_to :car
end
class CreateWheels < ActiveRecord::Migration

2. def self.up
create_table :wheels do |t|
t.references :car
t.timestamps
end
end
ActiveRecord Products.connection.execute('UPDATE `products` SET `price`=`free` WHERE 1') If the helpers not enough
Rename column script/generate migration rename_my_column_by_hand
Then edit the file it creates:
class RenameMyColumnByHand <
ActiveRecord::Migration
def self.up
rename_column :my_table, :old_name, :new_name
end
def self.down
rename_column :my_table, :new_name, :old_name
end
end
It executes SQL like:
ALTER TABLE my_table CHANGE old_name new_name
BIGINT;
Change type of
column
class AddColumnToTable < ActiveRecord::Migration
def change
add_column :table, :column, :type
end
end
Rails g migration changetypecolumn
Add column rails generate migration add_password_to_users password:string rails generate migration add_columnname_to_tablename

3. columnname:datatype