Introduction to PHP and MySQL

What is PHP?

PHP is a widely-used general-purpose server-side scripting language that can be embedded into HTML. 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. If you are new to PHP and want to get some idea of how it works, try the introductory tutorial.

PHP Home Page
Manual
Download

What is MySQL?

MySQL is a relational database management system, or RDBMS. It has become the world's most popular open source database because of its consistent fast performance, high reliability and ease of use. PHP has MySQL extension which makes it really easy to access data in MySQL.

MySQL Home Page
Manual
Download

Useful MySQL Database Administration Tools

phpMyAdmin (freeware)

Installing PHP and MySQL on Windows

Both PHP and MySQL support various platforms, including Windows. It is recommended that you install MySQL and PHP on your computer so you can easily develop and test your PHP locally before uploading to your production server.

You can install PHP on your Windows system using the Windows PHP installer which installs the CGI version of PHP for IIS, it configures the web server as well. However, while the Windows installer is an easy way to make PHP work, it does not include any extra external PHP extensions (e.g. php_mysql.dll) as you'll only find those in the Windows Zip Package.

As with enabling any PHP extension (such as php_mysql.dll), the PHP directive extension_dir should be set to the directory where the PHP extensions are located. An example extension_dir value for PHP 5 is C:\PHP\ext

Note: If when starting the web server an error similar to the following occurs: "Unable to load dynamic library './php_mysql.dll'", this is because php_mysql.dll and/or libmysql.dll cannot be found by the system. In that case, you can try copy the files into the Windows system directory, this is because this directory (e.g. C:\Windows) is by default in the systems PATH. However, note that PHP manual states that copying files into the Windows system directory has long since been deprecated and may cause problems.

In addition to PHP itself, you will need a Web server such as Internet Information Services (IIS) or Apache. PHP was designed to run as a plug-in for existing Web server software. If you have Windows 2000 or later, then install IIS (if it's not already on your system, see below section). If you do not have IIS at your disposal, you can instead use a free 3rd party Web server like Apache.

If you have difficulties installing PHP and MySQL, you might as well try EasyPHP which is an "out of the box" Apache, MySQL, and PHP installation for Windows. However, EasyPHP might not includes the latest versions of PHP and MySQL, but they are already good enough for development.

The next step is to set up a valid configuration file for PHP, php.ini. PHP searches for php.ini in the locations described in The configuration file.

Note: If you're using NTFS on Windows 2000 or later, make sure that the user running the web server (usually IUSR_<MachineName>) has read permissions to your php.ini (e.g. make it readable by Everyone).

Some Important Settings in php.ini for Using PHP on Windows

session.save_path

This is the path where session data files are stored. Make sure this setting points to an existing folder on your machine. For example,

session.save_path = C:\PHP\sessiondata

Note: If you're using NTFS on Windows 2000 or later, make sure that the user running the web server has write permissions to this folder (e.g. make it readable and writable by Everyone). See the section Configuring Permissions below.

upload_tmp_dir

If you want to use file upload, make sure this setting points to an existing folder on your machine. For example,

upload_tmp_dir = C:\PHP\uploadtemp

Note: If you're using NTFS on Windows 2000 or later, make sure that the user running the web server has write permissions to this folder (e.g. make it readable and writable by Everyone). See the section Configuring Permissions below.

Internet Information Services (IIS)

Internet Information Services (IIS) – formerly called Internet Information Server – is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows. It is an integral part of Windows Server family of products, as well as certain editions of Windows XP, Windows Vista and Windows 7. IIS is not turned on by default when Windows is installed. Versions:

• IIS 5.0, Windows 2000
• IIS 5.1, Windows XP Professional and Windows XP Media Center Edition (requires retail CD)
• IIS 6.0, Windows Server 2003 and Windows XP Professional x64 Edition
• IIS 7.0, Windows Server 2008 and Windows Vista (Home Premium, Business, Enterprise and Ultimate editions)
• IIS 7.5, Windows Server 2008 R2 and Windows 7 (Home Premium, Professional, Enterprise and Ultimate editions)

After installation, the default web directory to place the web site is in 'C:\Inetpub\wwwroot', but you can always set up your own virtual directory through the IIS Manager. For more information, see Creating Virtual Directories in IIS below.

Local IIS Web Sites

A local Internet Information Services (IIS) Web site is an IIS Web application on your computer. Creating or opening a local IIS Web site is useful in the following situations:

• You want to test your Web site using IIS, which closely emulates how the Web site will run on a production server. This can have advantages over working with file system Web sites that run using the PHP development server, because paths are resolved as they will be on a production server.
  
  
• You already have a set of Web site files in a folder and you want to test the Web site with IIS. In this case, you can create a virtual directory in your local version of IIS.
  
  
• Your local computer is also your Web server.

Requirements
To create a local IIS Web site requires the following:

• Your computer must have at least IIS version 4.0 installed and running.
  
  
• PHP must be enabled in IIS version 6.0. To enable PHP by using IIS Manager, expand the local computer, and then click Web Service Extensions. In the details pane, click php, and then click Allow.
  
  
• You must be logged in as a user with administrative privileges. This is required because working with the IIS metabase (where information about IIS applications is stored) requires administrative privileges.

To open an existing local IIS Web site, the preceding must be true as well as the following:

• The site to be opened must be configured as an IIS application. For more information, see Creating Virtual Directories in IIS below.
  

Note: You can create an IIS application as a subfolder of any existing IIS folder.

Running Local IIS Web Sites
When you run a local IIS Web site to test it, launches a browser and runs the Web site using the server name localhost. For example, if you have created the Web site ExampleSite, when you test it, go to the following URL:
http://localhost/ExampleSite/
IIS resolves the application name, whether it points to a folder that is under the IIS root or to another location, and serves pages from that folder.

Deploying Local IIS Web Sites
Local IIS Web sites are generally used only for development, so that individual developers can create and test PHP Web pages on their own computers. In most cases, you must deploy the files from a file system Web site to a production server that is running IIS or Apache.

Creating Virtual Directories in IIS

In most cases, the content you publish to your website is located in a root or home directory on your computer, such as C:\Inetpub\wwwroot\. However, there might be instances when the content is located somewhere else, or even on a remote computer.

To publish from any directory not contained within your home or root directory, you can create a virtual directory. A virtual directory is a directory that is not contained in the home directory but appears to client browsers as though it were.

You can create a virtual directory through IIS Manager or by using Windows Explorer.

Important: You must be a member of the Administrators group on the local computer to perform the following procedures.

To create a virtual directory by using IIS Manager

1. In IIS Manager, expand the local computer, expand the Web Sites folder, right-click the site or folder within which you want to create the virtual directory, point to New, and then click Virtual Directory. The Virtual Directory Creation Wizard appears.
   
   

   

   
   
   
2. Click Next.
   
   
3. In the Alias box, type a name for the virtual directory. (Choose a short name that is easy to type because the user types this name.)
   
   

   

   
   
   
4. Click Next.
   
   
5. In the Path box, type or browse to the physical directory in which the virtual directory resides, and then click Next.
   
   
   

   

   
   
   
6. Under Allow the following permissions, select the check boxes for the access permissions you want to assign to your users, you must select Read and Run scripts, and then click Next.
   
   Note: The IIS Manager UI only configures settings at the IIS scope, so the "Read", "Write", "Script source access", and "Directory browsing" check boxes only affect IIS-level behavior. These access controls in IIS have nothing to do with allowing/denying writing to file or uploads, so enabling "Read" while disabling "Write", "Script source access", and "Directory browsing" definitely do nothing as far as denying writing to a file or uploads is concerned. Also see Configuring Permissions below.
   
   
   

   

   
   
   
7. Click Finish. The virtual directory under the default website is created at the selected folder and is displayed in the IIS manager.
   
   

   

   
   Note that the virtual directory setup as an application is displayed with a icon. (The screenshot is from Windows 2003 server. The icon may be different in other versions of Windows. If the virtual directory is not an application, it is displayed with a icon.)
   
   Right-click the Virtual Directory and then click Properties. If the virtual directory is an application, the button next to [Application name] will be displayed as [Remove]. Otherwise, the button will be displayed as [Create] and you can click to make the virtual directory an application.
   
   For real websites, e.g. if you use Web hosting, the application is usually setup at the root of the website by the hosting provider. For local IIS website during development, the application is usually a virtual directory under the Default Web Site.
   
   
   

   

To create a virtual directory by using Windows Explorer

1. Open Windows Explorer.
   
   
2. Right-click the folder you want to be a virtual directory, and click Sharing and Security.
   
   
3. Click the Web Sharing tab.
   
   

   

   
   
   
4. Click Share this folder.
   
   
5. In the Alias box, type the name for the virtual directory.
   
   
6. Click OK twice.

Creating Virtual Directories in IIS 7 (Windows Vista or Later)

The IIS manager user interface consists of three panes.

The left hand side pane is Connections, the middle pane is Workspace and the right hand side pane is Actions.

The Connections pane lists application pools and websites. The workspace pane consists of two tabs at the bottom namely Features View and Content View. The Features View allows you to work with the settings of the selected item from Connections pane whereas the Content View displays all the child nodes (content) of the selected item.

Application pool is a group of IIS applications that are isolated from other application pools. Each application pool runs in its own worker process. Any problem with that process affects the applications residing in it and not the rest of the applications. You can configure application pools individually.

In order to create a new application pool, select "Application Pools" under Connections pane. Then click on "Add application pool" from Actions pane. This will open a dialog as shown below:

Specify a name for the new pool to be created. Select .NET framework version that all the applications from the pool will use. Also select pipeline mode. There are two pipeline modes viz. integrated and classic. The integrated mode uses the integrated request processing model whereas the classic mode uses the older request processing model. Click OK to create the application pool.

Your new application pool will now be displayed in the Workspace pane. To configure the application pool click on the "Advanced Settings" option under Actions pane. The following figure shows many of the configurable properties of an application pool.

If you use 64-bit Windows, set Enable 32-Bit Applications to True. (See Running on 64-bit Windows Operating System below.)

Here, you can specify properties of the new web site including its application pool and physical location.

An existing Virtual directory can be marked as an IIS application by right clicking on it and selecting "Convert to Application".

You may encounter the following error messages when you run PHP pages with IIS 7:

"An error occurred on the server when processing the URL. Please contact the system administrator"

Go to Internet Options->Advanced, disable "Show friendly HTTP error messages".

Configuring Permissions

An important aspect of working with files on the Web server is to correctly configure permissions, especially when the web application needs to write file on the server..

When a Web application uses a file, the application must have Read permission to the file so the application can access the data. Additionally, the application must have Write permission to the folder that contains the file. Write permission is required because the file may be created at run time.

If you use Linux/Unix, CHMOD your upload folder to "777" by using your FTP software.

If you use IIS, the anonymous IIS user is IUSR_<MachineName> by default. Therefore, to read/write a file in an PHP Web application, you must configure the folder that contains the file to have both Read and Write permissions for the IUSR_<MachineName> user account.

To set permissions in the folder (if you're using NTFS on Windows 2000 or later),

1. In Windows Explorer, move to the root folder for the Web site. e.g. C:\Inetpub\wwwroot\ExampleSite.
2. If the folder does not already exist, create one.
3. Right-click the folder, click Properties, and then click the Security tab.
   
   

   

4. Under Group or user names, look for IUSR_<MachineName>.
5. Verify that the account has Read and Write permissions for the folder.

Running on 64-bit Windows Operating System

Windows Server 2008 64-bit (IIS 7)

On 64-bit Windows 2008, IIS 7 can run both 32-bit and 64-bit worker processes simultaneously. To run 32-bit Web applications in IIS 7 on 64-bit Windows 2008 all it needs is to assign the 32-bit applications to a separate application pool in IIS and turn on the Enable 32-Bit Applications switch for that application pool. To do this, open IIS Manager, open Application Pool, select the application pool, and then click Advanced Settings. In Enable 32-Bit Applications, select True.

Windows Server 2003 64-bit (IIS 6)

On 64-bit Windows 2003, although IIS 6 supports running both 64-bit and 32-bit worker processes, it doesn't support running in both modes simultaneously. By default IIS 6 is configured to run in native 64-bit mode and work only with 64-bit worker processes, which means you can only run 64-bit Web applications (for ASP.NET applications they can only target ASP.NET version 2.0 or higher) in the native mode. In order to run 32-bit Web applications you will need to set IIS 6 to run in 32-bit mode. Note: This means all your Web applications will now run in 32-bit mode.

To enable IIS 6 to run 32-bit worker processes follow these steps:

1. Open a command prompt and navigate to the %systemdrive%\Inetpub\AdminScripts directory
2. Type the following command:
   cscript.exe adsutil.vbs set W3SVC/AppPools/Enable32BitAppOnWin64 "true"
3. Press ENTER
4. Afterwards restart IIS by using the iisreset command from the command-line

The following article explains the details of the changes in the behavior of IIS after configuring it to run 32-bit worker processes: Running 32-bit Applications on 64-bit Windows (IIS 6.0)