class2-prep

Module 7

Class 2 Prep

Before coming to Class 2, please complete the following tasks:

Lecture

Task	Resource Type	Link	Instructions
Watch	Lecture	Week 8	This lectures talks a little more about PHP before covering MVC, a "paradigm" for how to architect a large software application. Finally, we are also intorduced to SQL, a language for querying databases.
Watch	Lecture	Week 8, continued	This lecture deals with SQL in depth.

---

A Little More PHP

Task	Resource Type	Link	Instructions
Read	Lecture Notes	Week 8 / PHP	These notes review the role that the PHP Interpreter plays (kind of like the compiler in C, but a little different). They also discuss the chmod command for managing permissions on files. Finally, we are also introduced to string "interpolation", an alternative way of inserting values into strings in PHP.
Read	Resource	W3 Schools / extract()	In an upcoming walkthrough, David will use the extract() function. Read this article to learn what it does and see some examples.
Read	Resource	PHP Default Parameters	In an upcoming walkthrough, David will use a feature of PHP that allows you to specify "default values" for arguments that are passed into functions. Read this article to see some examples of how this works.

---

MVC

Task	Resource Type	Link	Instructions
Watch	Doug's Playlist	MVC	The MVC (Model - View - Controller) paradigm is a philosophy of how to organize the responsibilities of different parts of your application. In this video Doug explains why we want to use the MVC system, and what each of the three roles (M, V and C) is responsible for. He also shows how we can use the chmod command to set appropriate permissions on the various parts of our application.
Read	Lecture Notes	Week 8 / MVC	These notes introduce MVC and run through an example of restructuring a project to use it. (You will see this in more detail in the Walkthrough videso below).
Follow Along	Walkthrough	mvc-0	To start, we make a site with a series of very similar pages of hard-coded HTML. Surely this can be improved! You can find pseudocode to start this program here.
Follow Along	Walkthrough	mvc-1	First, we factor out much of the repeated HTML into one "header" and "footer" template. You can find pseudocode to start this program here.
Follow Along	Walkthrough	mvc-2	Now we write functions to render our header and footer, so that we can specify a different title for each page. You can find pseudocode to start this program here.
Follow Along	Walkthrough	mvc-3	Here, we condense our two renderHeader and renderFooter functions into a single render function that takes an additional parameter for the file ("header" or "footer"). You can find pseudocode to start this program here.
Follow Along	Walkthrough	mvc-4	Here, we improve the organization of our project by moving some files into separate subdirectories. Since those files have moved, we must go back and include the full file path to any require stateents in our code. You can find pseudocode to start this program here.
Follow Along	Walkthrough	mvc-5	Finally, we do a bit more re-organization, this time for security purposes. Any files that the user does not directly need to access, we relocate out of the public/ directory. You can find pseudocode to start this program here.

---

SQL

Task	Resource Type	Link	Instructions
Watch	Doug's Playlist	SQL	Doug talks about databases and SQL, bushing on all these topics: phpmyadmin, the SQL data types, primary keys, the basic SQL query commands: INSERT, SELECT, UPDATE, and DELETE, selecting with JOIN, and the query funciton in php
Follow Along	Resource	SQL Tutorial	Here we point you to some resources where you can get your fingers busy typing some SQL queries.
Watch	Short	SQL	Christopher goes over the main SQL commands using delicious cupcakes.
Read	Lecture Notes	Week 8, continued / SQL	These notes describe the various data types available in a MySQL database, and introduce a PHP function called query(), written by the CS50 folks, that allows us to make SQL queries within our PHP code.
Read	Resource	W3 Schools / SQL Quick Reference	This is a nice SQL syntax cheatsheet to have in your pocket.
Read	Lecture Notes	Week 8, continued / Transactions	These notes explain how sometimes you need to "lock" your SQL operations together into transactions, so that multiple operations are guaranteed to happen in sequence without interruption.
Read	Lecture Notes	Week 8, continued / SQL Injection	You should never interpolate user input directly into the strings that hold your SQL queries. Doing so makes you vulnerable to a SQL injection attack!
Read	Resource	W3 Schools / SQL Injection	This is optional This article provides a nice explanation of how SQL injection attacks work.

---

Now you're ready for Class 2