Date post: | 28-Oct-2014 |
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Business |
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Intro to PHP
Carl-Erik Svensson
What is PHP?
• PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML*
*Source: http://www.php.net
Why Use PHP?
• Simple, yet powerful scripting tool
• Easily format and display database information
• It is popular
Image Source: http://www.securityspace.com/s_survey/data/man.200709/apachemods.html
The Basics
The Results
• Output from a script goes directly into the HTML that is parsed
• This is what is meant by a ‘dynamic’ webpage
Some Syntax
• Generally C-like• Variables are not strongly typed
Web Applications
• Form processing
• Database manipulation
– Blogs– Forums– Facebook
PHP + MySQL = Sweet
• MySQL is an open source database software solution
• Enables rich web applications when combined with PHP
Image Source: http://www.mysql.com/
Rainfall Application
• Read the contents of a database
• Get the rainfall data
• Parse the results
• Display it
Connecting to a Database
• PHP Has a set of functions that can be used with MySQL
• First step is to setup a link to the desired database
Making a Query
• Once a link is established, querying is easy• Errors for any given function are returned by
mysql_error()
MySQL Result Set
• The value returned by mysql_query() is a reference to an internal data structure
• It can be parsed by various functions
Associative Arrays
• An array that can be indexed by a string• A set of key->value pairs• Very similar to a hash in Perl
PHP foreach
• Similar to the Perl equivalent• Allows iterating through each element of an
array
Put it All Together
The Results
http://128.174.242.224/PHPExamples/rainfall.php
A Slight Improvement
• This was not the exact code we came up with
• I added some titles and a neat trick– Highlight every other row in the table– This makes information more readable
Samples
• USGS Example Rainfall
• EC Awards Committee Scholarship Database
What Else Can PHP Do?
• Command line scripting
• Desktop applications
• Anything
Links
• PHP.net• PHP Manual• MySQL