Graduating from Khan Academy’s SQL course!
I wanted to write up a quick post to help out other people who are starting to learn SQL with MOOCs but who may be getting hella confused -- as I was! -- about how to start writing and running programs outside of in-browser playgrounds, like those on Khan Academy or Codecademy.
First, a disclaimer: I’m a total beginner at this, so while these steps have worked for me and were based on information from legit sources that I found through Googling, there may be far better ways to do the steps described below.
1) Start with familiarizing yourself with the Command Line Interface.
This is important because you’ll have to work on the command line a lot, and it will be difficult to move forward until you get at least a basic understanding of it.
This module out of the Johns Hopkins’ Data Scientist’s Toolbox Coursera course (facilitated by Jeffrey Leek) is really beginner-friendly: https://www.coursera.org/learn/data-scientists-tools/lecture/FhvlV/command-line-interface.
Another good beginner-friendly guide is Zed Shaw’s Learn Code The Hard Way CLI ebook http://cli.learncodethehardway.org/book/ (plus it touches on the dangers of using the “rm” command, which the Coursera module didn’t).
2) Start using a text editor.
This is really what took me longest to figure out: where to actually start writing the code. When I Googled this problem, it didn’t really yield very clear results because I didn’t really know what to Google for. Turns out all you really need is get yourself a text editor.
I chose Atom.io (built by Github) because this is what was being recommended for beginner on the forums that I visited, but there are many others, like Vim and Emacs. Textwrangler is what is used on the University of Michigan's Coursera course "Getting Started with Python” (facilitated by Charles Severance). Hell, I think even TextEdit, which comes with every Mac, and the Notepad, which comes with every Windows, will work.
3) Make sure you have SQLite installed on your machine.
If you’re working on a newish Mac like I am, you should already have SQLite preinstalled and you don’t need to install it again. You just have to verify it by opening up your Terminal and typing “sqlite3”. However, detailed instructions for installing, should you need to install, and for verifying that you’ve installed it, can be found at Tutorials Point here: http://www.tutorialspoint.com/sqlite/sqlite_installation.htm.
4) Use your text editor to write your SQL code.
The text editor is where you create and populate tables. It works just like the box on the lefthand side of most MOOC playgrounds, where you can type up your code based on the instructions. You can even copy-paste directly from one of your Khan Academy projects. Save the file with a .sql file extension, and pay attention to which folder in your computer you’re saving the file in. Ideally, it’s a folder that you can easily find on Finder.
5) Use the terminal to create a DB.
Use the “cd” command (one of the Command Line Interface commands that you would have learned in Step 1) to move to the folder in your machine where you saved your .sql file. Then, create a database while simultaneously executing the SQL that you wrote through your text editor earlier. Basically, type this:
# sqlite name_of_your_database.db < name_of_your_sql_file.sql
This should get you up and running! From here, you can continue experimenting with other commands, like viewing the names of the tables you’ve created by typing “.tables” or doing some SELECTs. These are all far better explained by legit tutorials for beginners — I used this SQL quickstart guide by the The Geek Stuff: http://www.thegeekstuff.com/2012/09/sqlite-command-examples/ as well as the chapter from ZetCode’s SQL tutorial on the sqlite3 command line http://zetcode.com/db/sqlite/tool/.
I hope this helps out at least one confused person out there!
ellievsbear
