backpackerhh

YourApp.register_provider :domain_events, namespace: true do # dry-system
  prepare do
    Dir[target.root.join("path/to/**/*_event_subscriber.rb")].each { |file| require file }

    register "subscribers", EventSubscriber.subclasses
  end

  start do
    register "bus", InMemoryEventBus.new
    register "async_bus", SidekiqEventBus.new

backpackerhh

-- 1. Find the names of all students who are friends with someone named Gabriel. 

SELECT H1.name
FROM Highschooler H1
INNER JOIN Friend ON H1.ID = Friend.ID1
INNER JOIN Highschooler H2 ON H2.ID = Friend.ID2
WHERE H2.name = "Gabriel";


-- 2. For every student who likes someone 2 or more grades younger than themselves, return that student's name and grade, and the name and grade of the student they like. 

backpackerhh

-- 1. Find the titles of all movies directed by Steven Spielberg.

SELECT title
FROM Movie
WHERE director = 'Steven Spielberg';


-- 2. Find all years that have a movie that received a rating of 4 or 5, and sort them in increasing order.

SELECT DISTINCT year

backpackerhh

Keybase proof

I hereby claim:

• I am backpackerhh on github.
• I am backpackerhh (https://keybase.io/backpackerhh) on keybase.
• I have a public key ASAbGAEAN_vx-W97CRO0GG3xEQReFKUk6y65OpxeZCaPugo

To claim this, I am signing this object:

backpackerhh

#!/bin/bash
# Removes old revisions of snaps
# CLOSE ALL SNAPS BEFORE RUNNING THIS
set -eu
snap list --all | awk '/disabled/{print $1, $3}' |
    while read snapname revision; do
        snap remove "$snapname" --revision="$revision"
    done

backpackerhh

<!-- 1. Return all countries with population between 9 and 10 million. Retain the structure of country elements from the original data. -->

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="country[@population &gt; 9000000][@population &lt; 10000000]">
    <xsl:copy-of select="." />
  </xsl:template>
  <xsl:template match="text()" />
</xsl:stylesheet>

backpackerhh

<!-- 1. Return the area of Mongolia. -->

<!-- Reminder: To return the value of an attribute attr, you must use data(@attr), although just @attr may be used in comparisons. You will need to remember this for some later questions as well. -->

//country[@name = "Mongolia"]/data(@area)


<!-- 2. Return the names of all cities that have the same name as the country in which they are located. -->

//city[name = parent::country/data(@name)]/name

backpackerhh

# Usage:
#
# class MyClass < ActiveRecord::Base
#   ...
#   validate :postal_code, spanish_postal_code: true # default message
#   validate :postal_code, spanish_postal_code: { message: '<Your message>' } # custom message
#   ...
# end
#
class SpanishPostalCodeValidator < ActiveModel::EachValidator

backpackerhh

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE countries [
  <!ELEMENT countries (country*)>
  <!ELEMENT country ((language|city)*)>
  <!ATTLIST country name CDATA #REQUIRED population CDATA #REQUIRED area CDATA #REQUIRED>
  <!ELEMENT language (#PCDATA)>
  <!ATTLIST language percentage CDATA #REQUIRED>
  <!ELEMENT city (name, population)>
  <!ELEMENT name (#PCDATA)>

backpackerhh

# Each subdivision can go down to 127 levels deep, and each DNS label can contain up to 63 characters,
# as long as the whole domain name does not exceed a total length of 255 characters.
class SubdomainValidator < ActiveModel::EachValidator
  def validate_each(object, attribute, value)
    return unless value

    reserved_names = %w[admin beta blog ftp imap mail pop pop3 sftp smtp ssl www]
    reserved_names += options[:reserved] if options[:reserved]
    
    object.errors[attribute] << 'cannot be a reserved name' if reserved_names.include?(value.downcase)