Ruby on Rails Programming syntax

Ruby on Rails Programming

Routing:
get 'demo/index'

match ':controller(/:action(/:id))', :via => :get
match ':controller(/:action(/:id))', :via => [:get, :post]
match ':controller(/:action(/:id(.:format)))', :via => :get

root "demo/index"

class DemoController < ApplicationController
end

layout false

def index
end

render('hello') #run other page

redirect_to(:controller => 'demo', :action => 'index')

redirect_to("amirrajabi.com")

<% code %>
<%= code %>

<%= 1+2 %>  =>3
<% target = "world" %>
<%= "Hello #{{target}}" %>

puts   => just render text on consule

<% 3.times do %>
<%= "AMIR" %>
<% end %>

variable
@instance_variable

<% target = "Amir" %>
<%= "hello #{target}" %>

@array = [1, 2, 3, 4, 5]
<% @array.each do |n| %>
<%= "#{n}-Rajabi, " %>
<% end %>

<% 3.times do %>
<%= "Amir" %>
<% end %>

<%= link_to('Hello Page', {:action => 'hello'}) %>
<%= link_to('Hello Page With Parameters!', {:action => 'hello', :page => 5, :id => 20}) %>

@id = params['id'].to_i
@page = params[:page].to_i

ID: <%= @id %>
Page: <%= params["page"] %>

Next page: <%= @page +1 %>

.to_i
.to.s
.to_a


MySQL----------------------
$ mysql -u root -p
SHOW DATABASES;
CREATE DATABASE db_name;
USE db_name;
DROP DATABASE db_name;
GRANT ALL PRIVILEGES ON db_name.* TO 'username'@'localhost' IDENTIFIED BY 'password';
SHOW GRANTS FOR 'username'@'localhost'

$ mysql -u username -p db_name

$ rake db:schema:dump     => for checking ok connection with database

$ rake -T    => list of all commands
$ rake -T db   => list of all db commands

$ rake db:schema:dump RAILS_ENV = development

$ rails g migration TableName

$ rails g model Name


migrate:
class CreateTopTens < ActiveRecord::Migration
  def up
    create_table :top_tens do |t|
      t.timestamps null: false
    end
  end
  def down
    drop_table :top_tens
  end
end

data type : string/text/integer/float/boolean/...
:limit
:default
:null
:precision
:scale

$ rake db:migrate VERSION=0
$ rake db:migrate:status
$ rake db:migrate VERSION=120920152230
$ rake db:migrate:up VERSION=120920152230
$ rake db:migrate:down VERSION=120920152230

add_column(table, column, type, option)
remove_column(table, column)
rename_column(table, column, new_name)
change_column(table, column, type, option)

add_index(table, column, option)
remove_index(table, column)
:unique => true/false
:name   => "your_custom_name"


Create Record in Table:

user = User.new
user.user_name = "Amir"
user.save

user = User.new(:first_name => "Amir", :last_name => "Rajabi", :username => "arajabi")
user.save

user = User.create(:first_name => "Amir", :last_name => "Rajabi", :username => "arajabi")

Update data on record:-------------------
user = User.find(2)
user.user_name = "Amir"
user.save

user = User.find(2)
user.update_attributes(:first_name => "amir", :last_name => "Rajabi")

Delete record:-------------------
user = User.find(2)
user.destroy
user.svae


find:----------------------------
user = User.find(1)
user = User.find_by_name("Amir")
user = User.all / .first / .last

users.each do |user|
  puts subject.name
end

User.where(:name => "Amir")

User.where("name LIKE ? OR job LIKE ?", ["Amir","Programmer"])

users.to_sql

User.where(:name => "Amir").first
.order
.limit
.offset

User.order("id ASC/DESC").lomit(20).offset(40)

scope :subject, lambda/-> { where(:name => "Amir")}
def self.subject
  where(:name => "Amir")
end

scope :sorted, -> { where("subject.position ASC")}
scope :search, -> { |query| where(["name LIKE ?", "%#{query}%"])}
scope :search, -> { where('game_name LIKE :search OR genre LIKE :search OR console LIKE :search', search: "%#{search}%")
scope :search, -> { search(keywords) }
def self.search keywords
    return Media.all if keywords.empty? #if field was empty back all content
    search_fields = BASIC_SEARCH_FIELDS #list of table fields
    search_array = search_fields.map { |f| "#{f} LIKE ?" } #create new array with "LIKE ?"
    search_str = search_array.join(' OR ') #Join all cells of array
    search_values = keywords.map { |k| "%#{k}%"} * search_fields.count #create new array and add keyword * field.length
    Media.where(search_str, *search_values) # serach in select field on db
end