HTML and CSS Reference
The most common relational database offered by web hosting providers is MySQL, an
open source database that's freely available. There are many other popular relational
databases, too, including Oracle, Microsoft SQL Server, and PostgreSQL (another free
database). For web applications, however, MySQL is the leader. All the applications I'm
going to discuss in particular work with MySQL. If you want to read more about it, the
manual is available online at http://dev.mysql.com/doc/.
All the applications discussed in this lesson run on a web server. When it comes to
hosted applications, you don't need to worry about the web server. That's the job of the
application provider. In cases where you are installing your own applications, it's up to
you to make sure your web server environment will work with your application. For
example, all the applications I'm going to discuss in detail are written in PHP. If you are
planning on deploying to a server running Microsoft Internet Information Services with-
out PHP support, you won't get these applications to run. Before you download and
attempt to install an application, check its requirements to make sure the server on which
you plan to deploy the application meets them.
If you lease server space from a web hosting provider, you may need to check with it
before installing your software to make sure it's compatible with their environment. For
example, in addition to big requirements such as PHP or MySQL, some software pack-
ages also require particular libraries or supplemental software packages to function prop-
erly. You might need to ask to find out whether your hosting provider has all the software
you need running in its environment. In some cases, a hosting provider will actually
install the software you need if you explain what you're trying to do.
There's another issue you might run into depending on what kind of access you have to
your server. Generally, two levels of access are available when it comes to web
providers: FTP access and shell access. If you have FTP access, you're allowed to upload
your files to the server, but you are not allowed to log in to the server and run commands
directly. Shell access provides a command-line interface to the server that enables you to
edit files directly on the server, move things around, and generally use the server more
like it's your own computer. If you don't have shell access to the server, you will have to
edit the configuration files for your application locally on your own computer and then
upload the files and test them on the server.