Web Systems Development (CSC-215) Lecture 7: Working with Databases

localhost/phpMyAdmin

phpMyAdmin on Remote Host

Set up sample database

Set up sample database

Add sample entry

Confirmation of entry

Confirmation of entry

Process Connect to MySQL Select the database to use Build a query string Perform the query Retrieve results and output to a web page Repeat 3-5 until all desired data has been retrieved Disconnect from MySQL

Standard (Deprecated) vs. MySQLi If you’re looking up tutorials, make sure to use MySQLi as covered in the lecture The textbook includes deprecated version of the same code as well for reference

Creating a Login File

Connecting to MySQL Server

Building and executing a query

Fetch Result

fetch_array() Can return 3 types of arrays MYSQLI_NUM MYSQLI_ASSOC Numeric, columns appear in the array in the order defined in the table MYSQLI_ASSOC Associative, each key refers to a column (by name) MYSQLI_BOTH Associative and numeric array

Example

Make connection

Deleting a record

Inserting a record

Create input form

Get all entries

Display all entries

Close

Sanitize

End of example

SQL Injection User verification code

Preventing SQL Injection Normal usage

Preventing SQL Injection Entry for user field

Deletion Example

PHP’s Magic Quotes Feature Automatically adds back slash to characters like single and double quotes Bypass and use mysql_real_escape_string()

Solution Disable special characters by prepending slashes using real_escape_string()

Preventing HTML Injection Example of maliciously inserted code, via, e.g., a form that displays its input XSS: Cross-Site Scripting

Use htmlentities() to convert

Embedding PHP in HTML

Document head

Setting up table

Set up calculation

Class Activity Set up a script that is similar to the Fibonacci one but instead of Fibonacci numbers, calculate the sum to n for each number S0 = 0 S1 = 0 + 1 = 1 S2 = 0 + 1 + 2 = 3 S4 = 0 + 1 + 2 + 3 = 6 S5 = 0 + 1 + 2 + 3 + 4 = 10 Print only two columns, Sn and the sum Set different colors for alternating rows

Lecture content adapted from chapter 10 of Learning PHP, MySQL, JavaScript, CSS & HTML5.