midhunkrishna

postgres=# \c nominatim;
You are now connected to database "nominatim" as user "postgres".
nominatim=# \di
                                               List of relations
 Schema |                         Name                          | Type  |   Owne
r   |           Table           
--------+-------------------------------------------------------+-------+-------
----+---------------------------
 public | idx_country_name_country_code                         | index | nomina
tim | country_name

midhunkrishna

# ..in general, 
require 'rails'
require File.expand_path("../config/application.rb", __FILE__)
Rails.application.initialize!

# fork fork fork

ENV['UNICORN_WORKERS'].times do
  fork do
    # child

midhunkrishna

# -*- encoding: binary -*-

# This is the process manager of Unicorn. This manages worker
# processes which in turn handle the I/O and application process.
# Listener sockets are started in the master process and shared with
# forked worker children.
#
# Users do not need to know the internals of this class, but reading the
# {source}[https://bogomips.org/unicorn.git/tree/lib/unicorn/http_server.rb]
# is education for programmers wishing to learn how unicorn works.

midhunkrishna

module ConcurrentExecutor
  class Error < StandardError
    def initialize(exceptions)
      @exceptions = exceptions
      super
    end

    def message
      @exceptions.map { | e | e.message }.join "\n"
    end

midhunkrishna

# from_cte_sql = ::Namespace::From.where_clause
# ..


from_table = Arel::Table.new(:from_lane)
to_table = Arel::Table.new(:to_lane)
rates_table = Arel::Table.new(:rates)

rates_table
  .join(from_table).on(rates_table[:from_id].eq(from_table[:id]))

midhunkrishna

#!/bin/bash

set -e

if ! grep -q xenial /etc/lsb-release
then
  echo "Adding PPA for up-to-date Node.js runtime. Give your password when asked."
  # sudo add-apt-repository ppa:chris-lea/node.js
  sudo add-apt-repository ppa:chris-lea/redis-server
else

midhunkrishna

SELECT DISTINCT(each_attribute ->> 'reference_number_field')
  AS reference_number
FROM deliveries
  CROSS JOIN json_array_elements(reference_numbers)
  AS each_attribute
WHERE (each_attribute -> 'reference_number_field')
  IS NOT NULL

midhunkrishna

The resume problem

• Write program which read following details from termial
  • Name
  • Age
  • Qualification
• Write these details to a text file

Notes:

• Use KISS principle

midhunkrishna

Caeser Cipher

• Read about Caeser Cipher
• Program should read from file and convert the entire text data, no need to convert special character
• The program should write to a file

Points

• Should be object oriented

• Program should be designed rather than written

• Finish on or before 9PM today

midhunkrishna

  class FileUploadPolicy < ApplicationPolicy
  def create?
    can_create = false
    FileUploadPolicy.creator_roles.each do |role|
      can_create = can_create || @user.send("#{role}?".to_sym)
    end
    can_create
  end