youjingwong’s gists

youjingwong / gist:18a4ca28ee632efa631a

Created November 14, 2014 14:33

	#1. Count the votes for Sen. Olympia Snowe, whose id is 524.
	SELECT COUNT(*) FROM votes WHERE politician_id = 524 ;

	#2. Now do that query with a JOIN statement without hard-coding the id 524 explicitly, querying both the votes and congress_members table.
	SELECT COUNT(*) FROM congress_members INNER JOIN votes ON congress_members.id = votes.politician_id WHERE congress_members.name = "Sen. Olympia Snowe" ;

	#3. How about Rep. Erik Paulsen? How many votes did he get?
	SELECT COUNT(*) FROM congress_members INNER JOIN votes ON congress_members.id = votes.politician_id WHERE congress_members.name = "Rep. Erik Paulsen" ;

	#4. Make a list of Congress members that got the most votes, in descending order. Exclude the create_at and updated_at columns.

youjingwong / main.css

Last active August 29, 2015 14:08 — forked from nextacademy-private/main.css

	.container {
	/*
	If you have a block-level element of a certain width, margin: 0 auto;
	will how you center it inside its parent container.

	See: http://bluerobot.com/web/css/center1.html

	Don't change the container width.
	*/
	margin: 0 auto;

youjingwong / Cohort.rb

Last active August 29, 2015 14:07

ActiveRecord, Jr. 2: SQL Be Gone

	class Cohort < Database::Model

	def self.length
	all.length
	end

	self.attribute_names = [:id, :name, :created_at, :updated_at]

	attr_reader :attributes, :old_attributes

youjingwong / cohort.rb

Created October 16, 2014 06:27

ActiveRecord, Jr. 1: A Basic ORM

	class Cohort < Database::Model
	def self.all
	Database::Model.execute("SELECT * FROM cohorts").map do \|row\|
	Cohort.new(row)
	end
	end

	def self.length
	all.length
	end

youjingwong / gist:e5ea876ff874960ae869

Created October 16, 2014 02:04

Student Roster DB from Schema

	require 'sqlite3'

	$db = SQLite3::Database.new "students.db"

	module DBManipulate
	def self.add(first_name, last_name, gender, birthday, email, phone)
	$db.execute(
	<<-SQL
	INSERT INTO students
	(first_name, last_name, gender, birthday, email, phone, created_at, updated_at)

youjingwong / gist:40f6adb47a82f96bee47

Created October 15, 2014 08:29

	http://minus.com/i/bcPwh2BjwNXLY

	<?xml version="1.0" encoding="utf-8" ?>
	<!-- SQL XML created by WWW SQL Designer, http://code.google.com/p/wwwsqldesigner/ -->
	<!-- Active URL: http://ondras.zarovi.cz/sql/demo/ -->
	<sql>
	<datatypes db="mysql">
	<group label="Numeric" color="rgb(238,238,170)">
	<type label="Integer" length="0" sql="INTEGER" quote=""/>
	<type label="TINYINT" length="0" sql="TINYINT" quote=""/>

youjingwong / gist:1b23445d4fd7331bcb09

Last active August 29, 2015 14:07

Poll Design Schema

	http://minus.com/i/bmX1aLTg2JoD2

	<?xml version="1.0" encoding="utf-8" ?>
	<!-- SQL XML created by WWW SQL Designer, http://code.google.com/p/wwwsqldesigner/ -->
	<!-- Active URL: http://ondras.zarovi.cz/sql/demo/ -->
	<sql>
	<datatypes db="mysql">
	<group label="Numeric" color="rgb(238,238,170)">
	<type label="Integer" length="0" sql="INTEGER" quote=""/>
	<type label="TINYINT" length="0" sql="TINYINT" quote=""/>

youjingwong / sample.unsolved.txt

Last active August 29, 2015 14:07 — forked from nextacademy-private/sample.unsolved.txt

You Jing Wong youjingwong