Secure PHP Development- P158 pot

Now suppose we want to create another application that deals with PocketPCs.Because PocketPCs are really PDAs with specific operating system Windows CE requirements, we can easily inheri

Now suppose we want to create another application that deals with PocketPCs.

Because PocketPCs are really PDAs with specific operating system (Windows CE) requirements, we can easily inherit the PDA class and define a new class called PocketPC as follows:

<?php require_once ‘class.PDA.php’;

class PocketPC extends PDA { function printSpec($type = null) {

echo “CPU : “ $this->getCPU() “<br>”;

echo “RAM : “ $this->getRAM() “<br>”;

echo “TYPE : “ $this->getType() “<br>”;

echo “Windows CE Only System <br>”;

} }

?>

In the preceding example, we have extended PDA and overridden the

printSpec() method, as we want to print the fact that PocketPCs only run the Windows CE operating system Therefore, an application such as the following can use this class:

<?php require_once ‘class.PocketPC.php’;

$info[‘CPU’] = ‘StrongArm 400 Mhz’;

$info[‘RAM’] = ‘512 GB’;

$info[‘TYPE’] = ‘PDA’;

$myGizmo = new PocketPC($info);

$myGizmo->printSpec();

?>

This will output the following:

CPU : StrongArm 400 Mhz RAM : 512 GB

TYPE : PDA Windows CE Only System

The classes discussed so far clearly show the power of OOP Notice how we over-ride the PDA’s printSpec()method in the PocketPC class, but retain all the other benefits of the PDA, which happens to be a Computer object

Appendix C

MySQL Primer

M Y SQL IS THE MOST POPULAR open-source database in the world Its popularity stems from the following:

◆ MySQL is free as long as you don’t sell it to someone, sell a product that

is bundled with it, or install and maintain it at a client site If you’re in doubt about whether you fit within the license parameters, please see the Web site at http://www.mysql.com/

◆ MySQL supports many programming interfaces, including PHP, C, C++, Java, Perl, and Python The possibilities it offers to tailor programs to fit your needs are virtually limitless

◆ MySQL uses very fast methods of relating tables of information to one

another Using a method called a one-sweep multijoin, MySQL is very

effi-cient at gathering the information you request from many different tables

at once

◆ MySQL is widely used Chances are good that many other people have done something similar to what you are doing If you have questions or problems, you have a wide group of people to consult Not only can you get advice from others about what to do, you can also get valuable

infor-mation about what not to do This prevents you from making the same

mistakes others have made

MySQL is available all over the Internet The best way to get MySQL is to go to

http://www.mysql.com/and find a mirror site close to you You can find out how

to install MySQL on a Linux platform in Appendix D

763

Using MySQL from the Command-Line

You can start the MySQL client program by typing the following:

mysql -u username -p

In this example, username is the username you are using to access the SQL server If a password is required, you are prompted for it You should now see some-thing like the following:

Welcome to the MySQL monitor Commands end with ; or \g.

Your MySQL connection id is 143 to server version: 3.23.52 Type ‘help;’ or ‘\h’ for help Type ‘\c’ to clear the buffer.

mysql>

Creating a database

When you install MySQL, you have no data In fact, you don’t even have a database defined, other than the ones provided by MySQL itself In this section, we will cre-ate a database called store The syntax for this, at the mysql>prompt is simply

create database store;

You should get a response similar to the following:

Query OK, 1 row affected (0.02 sec)

This generic response indicates that your command has executed You can con-firm this by issuing the following command:

show databases;

Your rights to create, change, or delete databases depends on your account and the rights associated with it If you have root access you can (of course)

do just about anything, including set parameters for other accounts This chapter assumes that you have enough access to create and change data-bases If you do have root access to MySQL, be sure to set/change the root password after installing MySQL!

If this is the first database you create, you see the following:

+ -+

| Database | + -+

| mysql |

| test |

| store | + -+

1 row in set (0.00 sec)

Make sure you terminate each SQL query with a semicolon Without a semi-colon terminator, you will see another prompt line and your query will not

be executed.

There it is You now have a database named storethat contains no data Now it

is up to you to create the tables that store the data You need to define not only the names of all the columns, but also the types of data they store Begin by identify-ing the database you’re goidentify-ing to use by issuidentify-ing the followidentify-ing command:

Use store;

Then issue the following command to make the first table:

create table customers (

id INT AUTO_INCREMENT PRIMARY KEY, name CHAR(40) NOT NULL,

address CHAR(80), telephone CHAR(13));

Let’s examine each of these lines to see what it does, beginning with the first:

id INT AUTO_INCREMENT PRIMARY KEY,

This line is the meat of the table In it, you are creating a column named idthat holds whole numbers (intstands for integer) Additionally, this column is the

pri-mary key A pripri-mary key provides a convenient element to access the data in an orderly fashion For example, in our database the records will be stored with unique integers as their primary key Later, to access a record you could use a query to specify what record(s) to return by using that key Searching for matches with a pri-mary key is significantly faster than other fields