Build Your Own Database Driven Website Using PHP & MySQL: Pt. 1

Thursday Jan 3rd 2002 by Kevin Yank
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Together, PHP & MySQL form the most widely used open source database and scripting technologies on the Web today. Part 1 of our series of excerpts from this SitePoint title covers PHP & MySQL installation and your first PHP script.

Build Your Own Database Driven Website Using PHP & MySQL is a hands-on guide to learning all the tools, principles and techniques needed to build a fully functional database-driven Website using PHP & MySQL.

This book covers everything from installing PHP & MySQL under Windows or Linux, through to building a live Web-based content management system.

It also covers more advanced topics such as the storage of binary data in MySQL, and cookies and sessions in PHP, and comes complete with a set of PHP and MySQL reference tables that include PHP and MySQL syntax, functions, column types and more.

This book not only provides easy access to all the code samples demonstrated, but, more importantly, it leaves you with the confidence and know-how to adapt the principles and techniques to your own Web design projects.

What Will You Learn?

This book will show you how to:

  • Build a working Content Management System
  • Add, edit & delete Web content without using HTML
  • Setup automatic backups of your database
  • Increase your database security
  • Optimize the loading time of your Website
  • Build an ecommerce shopping cart
  • Automatically send email on triggered events
  • Handle file uploads using HTML forms
  • Build a Web-based file repository or photo gallery
  • Utilize sessions and cookies to track site visitors
  • Master MySQL Database Administration
  • And a whole lot more

Who Should Read This Book?

Build Your Own Database Driven Website Using PHP & MySQL is an essential resource for budding Web Developers. If you want to go beyond the limitations of a static site and learn to build dynamic, database-driven Websites, this book will show you how.

If you've never built a database-driven Website, this book was written for you. If you have, it's an extremely handy desk reference and an essential addition to your technical library.

Build Your Own Database Driven Website Using PHP & MySQL book cover Title: Build Your Own Database Driven Website Using PHP & MySQL
ISBN: 0-9579218-0-2
$34.95 (US)
Publication Date: August 2001
Pages: 242
SitePoint Pty. Ltd.

Welcome to the Show

Hi there, and welcome to the first in SitePoint.com's four-part series on building a database-driven Web site! Over the course of this series, it will be my job to guide you as you take your first steps beyond the HTML-and-JavaScript world of client-side site design. Together we'll explore what it takes to build the kind of large, content-driven sites that are so successful today, but which can be a real headache to maintain if they aren't done right.

Before we get started, you need to gather together the tools you'll need for the job. In this first chapter, I'll guide you as you download and set up the two software packages you'll need: PHP and MySQL.

PHP is a server-side scripting language. You can think of it as a "plug-in" for your Web server that will allow it to do more than just send plain Web pages when browsers request them. With PHP installed, your Web server will be able to read a new kind of file (called a PHP script) that can do things like retrieve up-to-the-minute information from a database and insert it into a Web page before sending it to the browser that requested it. PHP is completely free to download and use.

To retrieve information from a database, you first need to have a database. That's where MySQL comes in. MySQL is a relational database management system, or RDBMS. Exactly what role it plays and how it works we'll get into later, but basically it's a software package that is very good at the organization and management of large amounts of information. MySQL also makes that information really easy to access with server-side scripting languages like PHP. MySQL is released under the GNU General Public License (GPL), and is thus free for most uses on all of the platforms it supports. This includes most Unix-based platforms, like Linux and even Mac OS X, as well as Windows 9x/ME/NT/2000.

If you're lucky, your current Web host may already have installed MySQL and PHP on your Web server for you. If that's the case, much of this chapter will not apply to you, and you can skip straight to the section entitled "If Your Web Host Provides PHP and MySQL" to make sure your setup is ship shape.

Everything we'll discuss in this series may be done on a Windows- or Unix-based server. The installation procedure will differ in accordance with the type of server you have at your disposal. The following two sections deal with installation on a Windows-based Web server, and installation under Linux (and other Unix-based platforms), respectively. Unless you're especially curious, you should only need to read the section that applies to you.

As I mentioned above, MySQL may be downloaded free of charge. Simply proceed to http://www.mysql.com/downloads/ and choose the recommended stable release (as of this writing, it is MySQL 3.23). Under the heading of Standard binary (tarball) distributions (which basically means the program doesn't need to be compiled, and is ready to run once you download it), find and click Windows 95/98/NT/2000 (Intel). If you're on a high-speed connection, you'll probably want to check out one of the download mirrors listed at http://www.mysql.com/downloads/mirrors.html to get a reasonable download speed. After downloading the file (it's about 12MB as of this writing), unzip it and run the setup.exe program contained therein.

Once installed, MySQL is ready to roll (barring a couple of configuration tasks that we'll look at shortly), except for one minor issue that only affects you if you're running Windows NT/2000/XP. If you use any of those operating systems, find a file called my-example.cnf in the directory to which you just installed MySQL. Copy it to the root of your C: drive and rename it to my.cnf. If you don't like the idea of a MySQL configuration file sitting in the root of your C: drive, you can instead name it my.ini and put it in your Windows directory (e.g. D:\WINNT if Windows 2000 is installed on drive D:). Whichever you choose, open the file in WordPad (Notepad is likely to display it incorrectly) and look for the following line:

# basedir = d:/mysql/

Uncomment this line by removing the '#' symbol at the start, and change the path to point to your MySQL installation directory, using slashes (/) instead of backslashes (\). For instance, I changed the line on my system to read as follows:

basedir = d:/Program Files/mysql/

With that change made, save the file and close WordPad. MySQL will now run on your Windows NT/2000/XP system! If you're using Windows 95/98/ME, this step is not necessary -- MySQL will run just fine as-installed.

Just like your Web server, MySQL is a program that should be run in the background so that it may respond to requests for information at any time. The server program may be found in the "bin" subfolder of the folder into which you installed MySQL. To make things complicated, however, there are actually several versions of the MySQL server to choose from:

  • mysqld.exe This is the basic version of MySQL if you run Windows 95, 98, or ME. It includes support for all advanced features, and includes debug code to provide additional information in the case of a crash (if your system is set up to debug programs). As a result of this code, however, the server might run a little slow, and I've generally found that MySQL is so stable that crashes aren't really a concern.
  • mysqld-opt.exe This version of the server lacks a few of the advanced features of the basic server, and does not include the debug code. It's optimized to run quickly on today's processors. For beginners, the advanced features are not a big concern. You certainly won't be using them while you complete the tasks in this series. This is the version of choice for beginners running Windows 95, 98, or ME.
  • mysqld-nt.exe This version of the server is compiled and optimized like mysqld-opt, but is designed to run under Windows NT/2000/XP as a service. If you're using any of those operating systems, this is probably the server for you.
  • mysqld-max.exe This version is like mysqld- opt, but contains advanced features that support transactions.
  • mysqld-max-nt.exe This version's similar to mysqld-nt, but has advanced features that support transactions.

All these versions were installed for you in the bin directory. If you're running on Win98x/ME I recommend sticking with mysql-opt for now -- move to mysqld- max if you ever need the advanced features. On Windows NT/2000/XP, mysqld-nt is my recommendation. Upgrade to mysqld-max-nt when you need more advanced features.

Starting MySQL is also a little different under WinNT/2000/XP, but this time let's start with the procedure for Win95/98/ME. Open an MS-DOS Command Prompt and proceed to the MySQL bin directory, then run your chosen server program:

C:\mysql\bin> mysqld-opt

Don't be surprised when you receive another command prompt. This command launches the server program so that it runs in the background, even after you close the command prompt. If you press Ctrl-Alt-Del to pull up the task list, you should see the MySQL server listed as one of the tasks that's active on your system.

To ensure that the server is started whenever Windows starts, you might want to create a shortcut to the program and put it in your Startup folder. This is just like creating a shortcut to any other program on your system.

On WinNT/2000/XP, you must install MySQL as a system service. Fortunately, this is very easy to do. Simply open a Command Prompt and run your chosen server program with the - install option:

C:\mysql\bin> mysqld-nt -install

This will install MySQL as a service that will be started the next time you reboot Windows. To manually start MySQL without having to reboot, just type this command (which can be run from any directory):

C:\> net start mysql

To verify that the MySQL server is running properly, press Ctrl- Alt-Del and open the Task List. If all is well, the server program should be listed on the Processes tab.

The next step is to install PHP. At the time of this writing, PHP 4.x has become well-established as the version of choice; however, some old servers still use PHP 3.x (usually because nobody has bothered to update it). I'll cover the installation of PHP4 here, so be aware that if you're still working with PHP3 there may be some minor differences.

Download PHP for free from http://www.php.net/ (or one of its mirrors listed at http://www.php.net/mirrors.php). You'll want the Win32 Binaries package, and be sure to grab the version that includes both the CGI binary and the server API versions if you have a choice.

In addition to PHP itself, you will need a Web server such as Internet Information Services (IIS), Apache, Sambar or OmniHTTPD. PHP was designed to run as a plug-in for existing Web server software. To test dynamic Web pages with PHP, you'll need to equip your own computer with Web server software, so that PHP has something to plug into. If you have Windows 2000/XP, then install IIS (if it's not already on your system): open Control Panel, Add/Remove Programs, Add/Remove Windows Components, and select IIS from the list of components. If you're not lucky enough to have IIS at your disposal, you can instead use a free Web server like Apache. I'll give instructions for both options in detail.

First, whether you have IIS or not, complete these steps:

  • Unzip the file you downloaded into a directory of your choice. I recommend C:\PHP and will refer to this directory from here onward, but feel free to choose another directory if you like.

  • Find the file called php4ts.dll in the PHP folder and copy it to the System32 subfolder of your Windows folder (e.g. C:\Windows\System32).

  • Find the file called php.ini-dist in the PHP folder and copy it to your Windows folder. Once there, rename it to php.ini.

  • Open the php.ini file in your favorite text editor (use WordPad if Notepad doesn't display the file properly). It's a large file with a lot of confusing options, but look for a line that begins with extension_dir and set it so that it points to the extensions subfolder of your PHP folder:

    extension_dir = C:\PHP\extensions

    A little further down, look for a line that starts with session.save_path and set it to your Windows TEMP folder:

    session.save_path = C:\WINDOWS\TEMP

    Save the changes you made and close your text editor.

Now, if you have IIS, follow these instructions:

  • In the Windows Control Panel, open Administrative Tools | Internet Information Services.
  • In the tree view, expand the entry labeled local computer, then under Web Sites look for Default Web Site (unless you have virtual hosts set up, in which case, choose the site you want to add PHP support to). Right-click on the Web Site and choose Properties.
  • Click the ISAPI Filters tab, and click Add.... In the Filter Name field, type PHP, and in the Executable field, browse for the file called php4isapi.dll in the sapi subfolder of your PHP folder (e.g. C:\PHP\sapi\php4isapi.dll). Click OK.
  • Click the Home Directory tab, and click the Configuration... button. On the Mappings tab click Add. Again choose your php4isapi.dll file as the executable and type .php in the extension box (including the '.'). Leave everything else unchanged and click OK. If you want your Web server to treat other file extensions as PHP files (.php3, .php4, and .phtml are common choices), repeat this step for each extension. Click OK to close the Application Configuration window.
  • Click OK to close the Web Site Properties window. Close the Internet Information Services window.
  • Again, in the Control Panel under Administrative Tools, open Services. Look for the World Wide Web Publishing service near the bottom of the list. Right-click on it and choose Restart to restart IIS with the new configuration options. Close the Services window.
  • You're done! PHP is installed!

If you don't have IIS, you'll first need to install some other Web server. For our purposes I'll assume you have downloaded and installed Apache server from http://httpd.apache.org/; however, PHP can also be installed on Sambar Server ( http://www.sambar.com/), OmniHTTPD ( http://www.omnicron.ab.ca/httpd/), and others.

Once you've downloaded and installed Apache according to the instructions included with it, open http://localhost/ in your Web browser, to make sure it works properly. If you don't see a Web page explaining that Apache was successfully installed, then either you haven't run Apache yet, or your installation is faulty. Check the documentation and make sure Apache is running properly before you install PHP.

If you've made sure Apache is up and running, you can add PHP support:

  • On your Start Menu, choose Programs, Apache httpd Server, Configure Apache Server, Edit Configuration. This will open the httpd.conf file in NotePad.

  • All of the options in this long and intimidating configuration file should have been set up correctly by the Apache install program. All you need to do is add the following three lines to the very bottom of the file:

    LoadModule php4_module c:/php/sapi/php4apache.dll
    AddType application/x-httpd-php .php .php3 .phtml
    AddType application/x-httpd-php-source .phps

    Be sure the LoadModule line points to the php4apache.dll file on your system, and note the use of slashes instead of backslashes.

  • Save your changes and close Notepad.

  • Restart Apache by choosing Programs, Apache httpd Server, Control Apache Server, Restart on the Start menu. If all is well, Apache will start up again without complaint.

  • You're done! PHP is installed!

With MySQL and PHP installed, you're ready to proceed to the "Post-Installation Setup Tasks" section below.

This section covers the procedure for installing PHP and MySQL under most current distributions of Linux. These instructions were tested under the latest versions of RedHat Linux and Mandrake Linux; however, they should work on other distributions such as Debian without much trouble. The steps involved will be very similar, if not identical.

As a user of one of the handful of Linux distributions available, you may be tempted to download and install the RPM distributions of PHP and MySQL. RPM's are nice, pre-packaged versions of software that are really easy to install. Unfortunately, they also limit the software configuration options available to you. If you already have MySQL and PHP installed in RPM form, then feel free to proceed with those versions, and skip forward to the "Post-Installation Setup Tasks" section. If you encounter any problems, you can always return here to uninstall the RPM versions and reinstall PHP and MySQL by hand.

Since many Linux distributions will automatically install PHP and MySQL for you, your first step should be to remove any old RPM versions of PHP and MySQL from your system. If one exists, use your distribution's graphical software manager to remove all packages with 'php' or 'mysql' in their names ('mod_php' is one that is often missed).

If your distribution doesn't have a graphical software manager, or if you didn't install a graphical user interface for your server, you can remove these from the command line. You'll need to be logged in as the root user to issue the commands to do this. Note that in the following commands, "%" represents the shell prompt, and doesn't to be typed in.

% rpm -e mysql
% rpm -e mod_php
% rpm -e php

If any of these commands tell you that the package in question is not installed, don't worry about it unless you know for a fact that it is. In such cases, it will be necessary for you to remove the offending item by hand. Seek help from an experienced user if you don't know how. If the second command runs successfully (i.e. no message is displayed), then you did indeed have an RPM version of PHP installed, and you'll need to do one more thing to get rid of it entirely. Open your Apache configuration file (usually /etc/httpd/conf/httpd.conf) in your favorite text editor and look for the two lines shown here. They usually appear in separate sections of the file, so don't worry if they're not together. The path of the libphp4.so file may also be slightly different (e.g. extramodules instead of just modules). If you can't find them, don't worry – it just means that the RPM uninstaller was smart enough to remove them for you.

LoadModule php4_module modules/libphp4.so
AddModule mod_php4.c

These lines are responsible for telling Apache to load PHP as a plug-in module. Since you just uninstalled that module, you'll need to get rid of these lines to make sure Apache keeps working properly. You can comment out these lines by adding a hash (#) at the beginning of both lines.

To make sure Apache is still in working order, you should now restart it without the PHP plug-in:

% /etc/rc.d/init.d/httpd restart

With everything neat and tidy, you're ready to download and install MySQL and PHP.

MySQL is freely available for Linux from http://www.mysql.com (or one of its mirrors listed at http://www.mysql.com/downloads/mirrors.html). Download the latest stable release (listed as "recommended" on the download page). You should grab the "Tarball" version under "Source downloads", with filename mysql-3.xx.xx.tar.gz.

With the program downloaded (it was about 10.5MB as of this writing), you should make sure you're logged in as root before proceeding with the installation, unless you only want to install MySQL in your own home directory. To begin, unpack the downloaded file and move into the directory that is created:

% tar xfz mysql-3.xx.xx.tar.gz
% cd mysql-version

Next, you need to configure the MySQL install. Unless you really know what you're doing, all you should have to do is tell it where to install. I recommend /usr/local/mysql:

% ./configure --prefix=/usr/local/mysql

After sitting through the screens and screens of configuration tests, you'll eventually get back to a command prompt. Be sure the configuration completed successfully. If you see an error message just before the configuration quit, you'll need to address the problem it's complaining about. On Mandrake 8.0, for example, it complained of "No curses/termcap library found". I simply installed the 'libncurses5-devel' package in Mandrake's Software Manager, and the configuration worked fine on a second attempt. Once configuration is complete, you're ready to compile MySQL:

% make

After even more screens of compilation (this could take as long as a half an hour on some systems), you'll again be returned to the command prompt. You're now ready to install your newly compiled program:

% make install

MySQL is now installed, but before it can do anything useful its database files need to be installed too. Still in the directory you installed from, type the following command:

% scripts/mysql_install_db

With that done, you can delete the directory you've been working in, which just contains all the source files and temporary installation files. If you ever need to reinstall, you can simply re-extract the mysql-version.tar.gz file.

With MySQL installed and ready to store information, all that's left is to get the server running on your computer. While you can run the server as the root user, or even as yourself (if, for example, you installed the server in your own home directory), the best idea is to set up on the system a special user whose sole purpose is to run the MySQL server. This will remove any possibility of someone using the MySQL server as a way to break into the rest of your system. To create a special MySQL user, you'll need to log in as root and type the following commands:

% /usr/sbin/groupadd mysqlgrp
% /usr/sbin/useradd -g mysqlgrp mysqlusr

By default, MySQL stores all database information in the var subdirectory of the directory to which it was installed. We want to make it so that nobody can access that directory except our new MySQL user. Assuming you installed MySQL to the /usr/local/mysql directory, use these commands:

% cd /usr/local/mysql
% chown -R mysqlusr.mysqlgrp var
% chmod -R go-rwx var

Now everything's set for you to launch the MySQL server for the first time. From the MySQL directory, type the following command:

% bin/safe_mysqld --user=mysqlusr &

If you see the message 'mysql daemon ended', then the MySQL server was prevented from starting. The error message should have been written to a file called hostname.err (where hostname is your machine's hostname) in MySQL's var directory. You'll usually find that this happens because another MySQL server is already running on your computer.

If the MySQL server was launched without complaint, the server will run (just like your Web or FTP server) until your computer is shut down. To test that the server is running properly, type the following command:

% bin/mysqladmin -u root status

A little blurb with some statistics about the MySQL server should be displayed. If you receive an error message, something has gone wrong. Again, check the hostname.err file to see if the MySQL server output an error message while starting up. If you retrace your steps to make sure you followed the process described above, and this doesn't solve the problem, a post to the SitePoint.com Forums will help you pin it down in no time.

If you want your MySQL server to run automatically whenever the system is running (just like your Web server probably does), you'll have to set it up to do so. In the share/mysql subdirectory of the MySQL directory, you'll find a script called mysql.server that can be added to your system startup routines to do this.

First of all, assuming you've set up a special MySQL user to run the MySQL server, you'll need to tell the MySQL server to start as that user by default. To do this, create in your system's /etc directory a file called my.cnf that contains these two lines:

[mysqld]
user=mysqlusr

Now, when you run safe_mysqld or mysql.server to start the MySQL server, it will launch as mysqlusr without your having to tell it to. All that's left to do is to set up your system to run mysql.server automatically at startup.

Setting up your system to run the script at startup is a highly operating system-dependant task. If you're not sure of how to do this, you'd be best to ask someone who knows. However the following commands (starting in the MySQL directory) will do the trick for most versions of Linux:

% cp share/mysql/mysql.server /etc/rc.d/init.d/
% cd /etc/rc.d/init.d
% chmod 500 mysql.server
% cd /etc/rc.d/rc3.d
% ln -s ../init.d/mysql.server S99mysql
% cd /etc/rc.d/rc5.d
% ln -s ../init.d/mysql.server S99mysql

NOTE: Under the current SUSE distribution of Linux, there is no init.d directory, just a symbolic link pointing back to /etc/rc.d; symbolic links for startup files should thus be directed to the /etc/rc.d directory (e.g. ln –s ../mysql.server S99mysql).

That's it! To test that this works, reboot your system and request the status of the server as before.

One final thing you might like to do for convenience sake, is to place the MySQL client programs, which you'll use to administer your MySQL server later on, in the system path. To this end, you can place symbolic links to mysql, mysqladmin, and mysqldump in your /usr/local/bin directory:

% ln -s /usr/local/mysql/bin/mysql /usr/local/bin/mysql
% ln -s /usr/local/mysql/bin/mysqladmin /usr/local/bin/mysqladmin
% ln -s /usr/local/mysql/bin/mysqldump /usr/local/bin/mysqldump

As mentioned above, PHP is not really a program in and of itself. Instead, it's a plug-in module for your Web server (probably Apache). There are actually three ways to install the PHP plug-in for Apache:

  • As a CGI program that Apache runs every time it needs to process a PHP-enhanced Web page.
  • As an Apache module compiled right into the Apache program.
  • As an Apache module loaded by Apache each time it starts up.

The first option is the easiest to install and set up, but it requires Apache to launch PHP as a program on your computer every time a PHP page is requested. This can really slow down the response time of your Web server, especially if more than one request needs to be processed at a time.

The second and third options are almost identical in terms of performance, but since you‘re likely to have Apache installed already, you'd probably prefer to avoid having to download, recompile, and reinstall it from scratch. For this reason, we'll use the third option.

To start, download the PHP Source Code package from http://www.php.net/ (or one of its mirrors listed at http://www.php.net/mirrors.php). At the time of this writing, PHP 4.x has become well-established as the version of choice; however, some old servers still use PHP 3.x (usually because nobody has bothered to update it). I'll be covering the installation of PHP4 here, so be aware that if you still work with PHP3 there may be some minor differences.

The file you downloaded should be called php- version.tar.gz. To begin, we'll extract the files it contains:

% tar xfz php-version.tar.gz
% cd php-version

To install PHP as a loadable Apache module, you'll need the Apache apxs program. This comes with most versions of Apache, but if you're using the copy that was installed with your distribution of Linux, you may need to install the Apache development RPM package to access Apache apxs. You should be able to install this package by whatever means your software distribution provides. By default, RedHat and Mandrake will install the program as /usr/sbin/apxs, so if you see this file, you know it's installed.

For the rest of the install procedure, you'll need to be logged in as the root user so you can make changes to the Apache configuration files.

The next step is to configure the PHP installation program by telling it which options you want to enable, and where it should find the programs it needs to know about (like Apache and MySQL). Unless you know exactly what you're doing, simply type the command like this (all on one line):

% ./configure
       --prefix=/usr/local/php
       --with-config-file-path=/usr/local/php
       --with-apxs=/usr/sbin/apxs
       --enable-track-vars
       --enable-magic-quotes
       --enable-debugger

Again, check for any error messages and install any files it identifies as missing. On Mandrake 8.0, for example, it complained that the 'lex' command wasn't found. I searched for 'lex' in the Mandrake package list and it came up with 'flex', which it described as a program for matching patterns of text used in many programs' build processes. Once that was installed, the configuration process went without a hitch. After you watch several screens of tests scroll by, you'll be returned to the command prompt. The following two commands will compile and then install PHP. Take a coffee break: this will take some time.

% make
% make install

PHP is now installed in /usr/local/php (unless you specified a different directory with the --prefix option of the configure script above) and it'll expect to find its configuration file, named php.ini, in the lib subdirectory (unless you specified a different directory with the -- with-config-file-path option of the configure script above). PHP comes with two sample php.ini files called php.ini-dist and php.ini- optimized. Copy these files from your installation work directory to the directory in which PHP expects to find its php.ini file, then make a copy of the php.ini- dist file and call it php.ini:

% cp php.ini* /usr/local/php/lib/
% cd /usr/local/php/lib
% cp php.ini-dist php.ini

You may now delete the directory from which you compiled PHP - it's no longer needed.

We'll worry about fine-tuning php.ini shortly. For now, we need to make sure Apache knows where to find PHP, so that it can load the program when it starts up. Open your Apache httpd.conf configuration file (usually /etc/httpd/conf/httpd.conf if you're using your Linux distribution's copy of Apache) in your favorite text editor. Look for a line that looks like this:

LoadModule php4_module lib/apache/libphp4.so

Find the new, uncommented line (no # at the start of the line), not the old line that you may have commented out earlier. It may not appear along with the other LoadModule lines in the file. Once you find it, you might need to change the path to match all the other LoadModule lines in the file. Under RedHat Linux, this means you'll have to change the line to make it look like this:

LoadModule php4_module modules/libphp4.so

PHP will probably run correctly without this change, but on older versions of RedHat, Apache won't be able to find the libphp4.so file until you make this change. If you prefer, leave the line alone for now -- you can come back and change it if you run into trouble.

Next, look for the line that begins with DirectoryIndex. In recent distributions, this may be in a separate file called commonhttpd.conf. This line tells Apache what filenames to use when it looks for the default page for a given directory. You'll see the usual index.html and so forth, but you need to add index.php, index.php3, and index.phtml to that list if they're not there already:

DirectoryIndex index.html ... index.php index.phtml index.php3

Finally, go right to the bottom of the file (again, this should go in commonhttpd.conf if you have such a file) and add these lines, to tell Apache which file extensions should be seen as PHP files:

AddType application/x-httpd-php .php .php3 .phtml
AddType application/x-httpd-php-source .phps

That should do it! Save your changes and restart your Apache server. If all things go to plan, Apache should start up without any error messages. If you run into any trouble, the helpful folks in the SitePoint.com Forums (myself included) will be happy to help.

No matter which operating system you're running, once PHP is installed and the MySQL server is in operation, the very first thing you need to do is assign a "root password" for MySQL. MySQL only lets authorized users view and manipulate the information stored in its databases, so you'll need to tell MySQL who is an authorized user, and who isn't. When MySQL is first installed, it's configured with a user named "root" who has access to do pretty much any task without even entering a password. Your first task should be to assign a password to the root user so that unauthorized users can't mess around in your databases.

It's important to realize that MySQL, just like a Web server or an FTP server, can be accessed from any computer on the same network. If you're working on a computer connected to the Internet that means anyone in the world could try to connect to your MySQL server! The need to pick a hard-to-guess password should be immediately obvious!

To set a root password for MySQL, type the following command in the bin directory of your MySQL installation (include the quotes):

mysqladmin -u root password "your new password"

To make sure MySQL has registered this change, you should tell it to reload its list of authorized users and passwords:

msqladmin -u root reload

If this command returns an error message to tell you that access was denied, don't worry: this just means the password has already taken effect.

To try out your new password, request that the MySQL server tell you its current status:

mysqladmin -u root -p status

Enter your password when prompted. You should see a brief message that provides information about the server and its current status. The "-u root" argument tells the program that you want to be identified as the MySQL user called "root". The "-p" argument tells the program to prompt you for your password before it tries to connect. The "status" argument just tells it that you're interested in viewing the system status.

If at any time you want to shut down the MySQL server, you can use the command below. Notice the usage of the same "-u root" and "-p" arguments as before:

mysqladmin -u root -p shutdown

With your MySQL database system safe from intrusion, all that's left is to configure PHP. To do this, we'll use a text file called php.ini. If you installed PHP under Windows, you should already have copied php.ini into your Windows directory. If you installed PHP under Linux using the instructions above, you should already have copied php.ini into the PHP lib folder (/usr/local/php/lib), or wherever you chose to put it.

Open php.ini in your favorite text editor and have a glance through it. Most of the settings are pretty well explained, and most of the default settings are just fine for our purposes. Just check to make sure that your settings match these:

register_globals = On
magic_quotes_gpc = On
doc_root = the document root folder of your Web server
extension_dir = the PHP extension directory

Save the changes to php.ini, and then restart your Web server. To restart Apache under Linux, log in as root and type this command:

/etc/rc.d/init.d/httpd restart

You're done! Now you just need to test to make sure everything's working okay.

If the host that provides you with Web space has already installed and set up MySQL and PHP for you and you just want to learn how to use them, there really isn't a lot you need to do. Now would be a good time to get in touch with your host and request any information you may need to access these services.

Specifically, you'll need a username and password to access the MySQL server they've set up for you. They'll probably have provided an empty database for you to use as well (which prevents you from messing with the databases of other users who share the same MySQL server), and you'll want to know the name of your database.

There are two ways you can access the MySQL server directly. Firstly, you can use telnet or secure shell (SSH) to log in to the host. You can then use the MySQL client programs (mysql, mysqladmin, mysqldump) installed there to interact with the MySQL server directly. The second method is to install those client programs onto your own computer, and have them connect to the MySQL server. Your Web host may support one or both of these methods, so you'll need to ask which.

If your host allows you to log in by telnet or SSH to do your work, you'll need a username and password for the login, in addition to those you'll use to access the MySQL server (they can be different). Be sure to ask for both sets of information.

If they support remote access to the MySQL server, you'll want to download a program that lets you connect to, and interact with, the server. This article series assumes you've downloaded from http://www.mysql.com/ a binary distribution of MySQL that includes the three client programs (mysql, mysqladmin, and mysqldump). Free packages are available for Windows, Linux and other operating systems. Installation basically consists of finding the three programs and putting them in a convenient place. The rest of the package, which includes the MySQL server, can be freely discarded. If you prefer a more graphical interface, download something like MySQL GUI (also available from http://www.mysql.com). I'd really recommend getting comfortable with the basic client programs first, though, as the commands you use with them will be similar to those you'll include in your PHP scripts to access MySQL databases.

Some less expensive Web hosts these days support neither telnet/SSH access, nor direct access to their MySQL servers. Instead, they provide a management console that allows you to browse and edit your database through your Web browser. Although this is a fairly convenient and not overly restrictive solution, it doesn't help you learn. Instead, I'd recommend the installation of a MySQL server on your own system to help, especially in the next chapter. Once you're comfortable working with your learning server, you can start using the server provided by your Web host with their management console. See the previous sections for instructions on installing MySQL under Windows and Linux.

It would be unfair of me to help you get everything installed and not even give you a taste of what a PHP-driven Web page looks like until Part 3, so here's a little something to whet your appetite.

Open up your favorite text or HTML editor and create a new file called today.php. Note that, to save a file with a .php extension in Notepad, you'll need to either select 'All Files' as the file type, or surround the filename with quotes in the Save As dialog; otherwise, Notepad will helpfully save the file as today.php.txt. Type this into the file:

<html>
<head>
<title>Today's Date</title>
</head>
<body>
<p>Today's Date 
(according to this 
  Web server) is
<?php

  echo( date("l, F dS Y.") );

?></p>
</body>
</html>

If you prefer, you can download this file along with the rest of the code in this article series here.

Save this and place it on your Web site as you would any regular HTML file, then view it in your browser. Note that if you view the file on your own machine, you cannot use the File, Open feature of your browser, because your Web server must intervene to interpret the PHP code in the file. Instead, you must move the file into the document root folder of your Web server software (e.g. C:\inetpub\wwwroot\ in IIS, or C:\Apache Group\Apache\htdocs\ in Apache for Windows), then load it into your browser by typing http://localhost/today.php. This allows the Web server to run the PHP code in the file and replace it with the date before it's sent to the Web browser. If you haven't yet had time to set up PHP on your Web server, click here to see the results on our server.

Pretty neat, huh? If you use the ‘View Source' feature in your browser, all you'll see is a regular HTML file with the date in it. The PHP code (everything between <?php and ?> in the code above) has been interpreted by the Web server and converted to normal text before it's sent to your browser. The beauty of PHP (and other server-side scripting languages) is that the Web browser doesn't have to know anything about it – the Web server does all the work!

And don't worry too much about the exact code I used in this example. Before too long you'll know it like the back of your hand.

If you don't see the date, then something is wrong with the PHP support in your Web server. Use View Source in your browser to look at the code of the page. You'll probably see the PHP code there in the page. Since the browser doesn't understand PHP, it just sees <?php ... ?> as one long, invalid HTML tag, which it ignores. Make sure that PHP support has been properly installed on your Web server, either in accordance with the instructions provided in previous sections of this article, or by your Web host.

Summary

You should now have everything you need to get MySQL and PHP installed on your Web Server. If the little example above didn't work right (for example, if the raw PHP code appeared instead of the date), something went wrong with your setup procedure. Drop by the SitePoint.com Forums and we'll be glad to help you figure out the problem!

In Part 2, you'll learn the basics of relational databases and get started working with MySQL. If you've never even touched a database before, I promise you it'll be a real eye opener! Meanwhile, I'd love to hear what you thought of the first part of this series of articles. Drop me a line at kevin@sitepoint.com, or stop by the SitePoint.com Forums to speak your mind.

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