Initial commit

## Example files for the title:  

# Understanding SQL and R, by Casimir Saternos

[![Understanding SQL and R, by Casimir Saternos](http://akamaicovers.oreilly.com/images/9781491970287/cat.gif)](https://www.safaribooksonline.com/library/view/title/9781491970294//)

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#!/bin/bash 

# Description:

# -----------

# This is script to create a directory structure matching the 

# course outline (Learning SQL with R: Tools for Data Science).

#

# Author: Casimir Saternos

#

cd Chapter\ 1

touch Chapter_1_Introduction.txt

mkdir 0101_Welcome_to_the_Course

mkdir 0102_About_the_Author

mkdir 0103_Course_Overview

mkdir 0104_Current_Context

mkdir 0105_Introduction_to_SQL

mkdir 0106_Introduction_to_R

mkdir 0107_Software_Installation

mkdir 0108_RStudio_Overview

mkdir 0109_R_Packages

mkdir 0110_The_Relationship_between_R_and_SQL

mkdir 0111_Demo_Application_and_Database_Schema_Overview

cd ..

cd Chapter\ 2

touch Chapter_2_SQL_with_Single_Table_Results_Sets.txt

mkdir 0201_Relational_Theory_Review

mkdir 0202_Results_Sets

mkdir 0203_Processing_Results_Sets_with_R

mkdir 0204_Filtering_and_Ordering_with_SQL

mkdir 0205_Grouping_and_Summarizing_SQL

mkdir 0206_Modify_Results_using_SQL_Functions

cd ..

cd Chapter\ 3

touch Chapter_3_SQL_with_Multiple_Tables.txt

mkdir 0301_Common_Database_JOINs

mkdir 0302_Less-common_JOINs

mkdir 0303_Subqueries

mkdir 0304_Set_Operations

mkdir 0305_DBA_Considerations

mkdir 0306_Table-like_objects

mkdir 0307_Indexes

cd ..

cd Chapter\ 4

touch Chapter_4_R_Packages_and_SQL-like_Results_Set_Processing.txt

mkdir 0401_SQL_Results_Set_and_Tidy_Data

mkdir 0402_Processing_Results_Sets_with_R_vs_SQL

mkdir 0403_Filtering_and_Ordering_with_dplyr_vs._SQL

mkdir 0404_Grouping_and_Summarizing_with_dplyr_vs._SQL

mkdir 0405_Modify_Results_using_dplyr_and_R_Functions

mkdir 0406_Joins_using_dplyr

mkdir 0407_Set_operations_using_dplyr

mkdir 0408_Reshape_package

mkdir 0409_RTidy_Package

cd ..

cd Chapter\ 5

touch Chapter_5_Data_Artifacts_using_SQL_and_R.txt

mkdir 0501_Plotting_Database_Results_with_R

mkdir 0502_Plots_using_Base_R_Plots

mkdir 0503_Plots_using_Lattice

mkdir 0504_Plots_using_ggplot2

mkdir 0505_Plotting_Time_Series_Data

mkdir 0506_Creating_Maps_with_R

mkdir 0507_Creating_Reports_with_R

mkdir 0508_Web_Applications_with_R

cd ..

cd Chapter\ 6

touch Chapter_6_Data_Sources_and_Connections.txt

mkdir 0601_Sample_Data_Sets

mkdir 0602_Database_File_Exports_and_Imports

mkdir 0603_Local_Relational_Databases_rsqlite

mkdir 0604_Non-relational_data_sources

mkdir 0605_Remote_Connections

mkdir 0606_Troubleshooting_remote_connections

mkdir 0607_RJDBC

cd ..

cd Chapter\ 7

touch Chapter_7_Additional_Topics.txt

mkdir 0701_Derived_Tables

mkdir 0702_Vendor_Specific_SQL

mkdir 0703_Non-SQL_inspired_and_SQL-like_languages

mkdir 0704_R_inside_the_Database

mkdir 0705_Schema_Design_Considerations

cd ..

cd Chapter\ 8

touch Chapter_8_Conclusion.txt

mkdir 0801_Wrap_Up_and_Thank_You

cd ..

# R as a calculator

2 + 4

# Read the file as a data frame

people <- read.csv("~/Desktop/oreilly/sql_and_r_course/Chapter 1/resources/people.txt", stringsAsFactors=FALSE)

View(people)

class(people)

# View() and class() above are examples of functions.  There are functions

# that perform all kinds of operations.  Here are some examples of string 

# functions:

nchar('Joe')

paste0('this','that')

# R has built in plotting capabilities

hist(nchar(people$first_name))

# Additional capabilities are available through R packages.  The ggplot2

# package provides even more graphical capabilities.

library(ggplot2)

# The equivalent histogram to the one created above using base R can be

# created with this call.

ggplot(people, aes(x=nchar(first_name))) + geom_histogram(binwidth = 1)

# Note R's interactivity.  

# Just an up - arrow will give you the previous line of history...

# so the previous line can be modified.  This is great for interactive

# data exploration or building up plots.

ggplot(people, aes(x=nchar(last_name))) + geom_histogram(binwidth = 1)

ggplot(people, aes(x=nchar(last_name), y=nchar(first_name))) + geom_point()

ggplot(people, aes(x=nchar(last_name), y=nchar(first_name))) + geom_point() + geom_jitter()

ggplot(people, aes(x=nchar(last_name), y=nchar(first_name))) + geom_point() + geom_density2d()

# As strings of function calls become longer, it is necessary to organize

# the code differently.  One option is to break up calls on to multiple lines.

ggplot(people, 

       aes(x=nchar(last_name), y=nchar(first_name), 

                   label= paste0(nchar(first_name),

                                ',',

                                nchar(last_name)

                                )

           )

       ) + geom_text(alpha=0.3, color='blue') + geom_density2d()

first_name,last_name,address

Alice,Atkins,123 Apple St.

John,Smith,234 Jefferson Rd.

Bob,Baker,5678 Benton Ln.

Aglae,Dibbert,6371 Jones Spurs

Alexander,Purdy,284 Reilly Squares

Alexandre,Wolf,338 Shanon Run

Allie,Hahn,77077 Kreiger Centers

Allison,Olson,6608 Torp Skyway

Andreanne,Weber,8171 Bernadine Greens

Andrew,Wunsch,18219 Carroll Unions

Annie,Friesen,35956 Corkery Village

Ara,Borer,80843 Kunze Island

Ardella,Howell,797 Keegan Valleys

Ashlee,Doyle,58352 Nichole Expressway

Ashton,Emard,412 Fahey Highway

Berneice,Donnelly,93700 Fisher Harbor

Bessie,Brekke,29246 Mueller Corners

Bettie,Tromp,909 Daugherty Walk

Birdie,Upton,98138 Devonte Coves

Boyd,Stanton,91516 Murphy Place

Buford,Wyman,190 Cortez Stravenue

Caleb,Lehner,217 Barrett Station

Christ,Rolfson,348 Rickie Vista

Clarissa,Braun,7588 Krajcik Port

Colby,Boyle,434 Fadel Land

Cynthia,Rippin,8364 Elda Ridge

Damon,Stanton,5842 Rosenbaum Trail

Dangelo,O'Kon,85714 Ritchie Highway

Danika,West,27511 Tracy Crest

Daron,Williamson,47932 Nigel Inlet

Davonte,Wehner,846 Katelin Crescent

Deanna,Kulas,57032 Abdiel Knolls

Desiree,Marvin,844 Welch Extension

Dolores,Kilback,315 Enoch Point

Domenick,Kuhic,7964 Willy Landing

Edwina,Legros,5400 Sven Fort

Eleazar,Greenholt,39212 King Ridge

Ellsworth,Walsh,7790 Johnny Lights

Eloy,Roob,6704 Jan Crescent

Elvie,Moore,9888 Torp Groves

Ernesto,Dooley,6320 Joaquin Road

Ezra,Goldner,539 Maryam Centers

Fanny,Adams,184 Beier Ports

Freddy,Larson,702 Celine Mews

Freeda,Klein,2363 Maiya Cliff

Freeman,Gislason,28624 Jerald Tunnel

Geraldine,Corwin,13410 Jo Fields

Gino,Zulauf,677 Elvera Parkway

Glen,Greenfelder,55416 Howell Ferry

Gracie,Cremin,1582 Howe Isle

Haley,Langworth,185 Cremin Court

Hellen,Aufderhar,19650 Goyette Trace

Hillary,Bergstrom,2785 Koss Meadow

Hillary,Legros,845 Gillian Lodge

Imelda,Hintz,814 Rosalyn Skyway

Jakayla,Stehr,9568 Sidney Neck

Janelle,Koepp,8251 Bechtelar Plaza

Jermey,Macejkovic,24802 Annetta Way

Josie,Hane,51555 Pascale Stravenue

Judson,Reichel,94797 Wolff Light

Julius,O'Conner,63304 Sarina Stream

Kane,Flatley,946 Yundt Crossing

Karley,Brakus,7093 O'Conner Groves

Kayleigh,Casper,8898 Kilback Pine

Kennedi,Wintheiser,3907 Mohr Fork

Kiel,Feest,6370 Hermina Square

Lane,Windler,9685 Gregorio Ports

Leda,Gusikowski,287 Candelario Centers

Leone,McCullough,239 Flatley Light

Leonel,Buckridge,202 Brakus Stream

Lillie,Stiedemann,258 Toy Orchard

Mackenzie,McCullough,5338 Jaron Curve

Mandy,Kilback,6672 Dicki Ridges

Marcelo,Green,5151 Thiel Views

Marvin,Ziemann,413 Douglas Spring

Maudie,Torp,6856 Rowland Branch

Maye,Schultz,2132 Jacobi Locks

Meggie,Erdman,253 Alessandro Lodge

Naomi,Bogisich,537 Johnnie Port

Nathanael,Von,1226 Florencio Lane

Noemi,Bosco,491 Corwin Falls

Ole,Reichert,68190 Letitia Greens

Oral,Willms,49630 Sarina Walks

Orrin,Stokes,627 Quigley Roads

Oswaldo,Donnelly,804 Spencer Crossroad

Reymundo,Bruen,236 Leffler Port

Rita,Reilly,135 Katrine Prairie

Rosalia,Leannon,8376 Wunsch Isle

Sadie,Volkman,5636 Alexandre Corners

Samir,Hilll,9189 Kiel Green

Sammie,Bins,2667 Llewellyn Flat

Sebastian,Schaefer,653 Bogan Mountain

Serenity,Lind,8451 Cara Station

Stevie,Rice,87686 Enoch Mountains

Sylvester,Hessel,396 Harber Trace

Tanya,Wuckert,728 Timmy Trafficway

Tiana,Pagac,99416 Champlin Viaduct

Tillman,Christiansen,3923 Lowe Crest

Timmy,Block,4230 Spencer Via

Verona,Ondricka,15131 Kaylee Trafficway

Webster,Schamberger,8168 Florian Terrace

Wilbert,Maggio,874 Nicolette Drives

Woodrow,Larson,267 Lew Islands

Zoe,Zetzger,999 Zebra Ave.

 No newline at end of file

# Strings are enclosed in either single or double quotes:

string1 <- "Behold, a string"

string2 <- 'If possible, use "double quotes" in single quoted strings...'

string3 <- "...and 'single quotes' in double quoted strings"

# To include a quote of the same kind use \ to escape the character:

string4 <- "A \"double quote\" inside of a double quote."

string5 <- 'A \'single quote\' inside of a single quote.'

print(string4)

# print will display the backslash character used to escape.

# If you want to avoid this when displaying a string in the

# console, message or cat

message(string5)  

# Cat is short for concatenate, and is used to display 

# one or more strings.

cat(string4,string5)

# This is for display only.  

long_string <- cat(string4,string5)

# Use paste for variable assignment...

long_string <- paste(string4,string5)

# and paste0 if you don't want a space added between each string

cat(paste0(string4,string5))