What about Data?

Linking to Databases

In the early days of the Internet most pages were static, they were like pages in a book that only changed when a webmaster updated them. Modern web pages are often 'dynamic', this means that the webpage is generated when a user requests it and often the page will change, depending on whet the user requires.

For example when you search google, the results you see in the search change, depending on what you type in the search box.

So how do dynamic web pages work?

Many dynamic web pages work by linking to databases. Information for a web page is held in a database, such as MS Access or MySql. The results that are displayed on a page depend on the options a the user selects. To make a dynamic webpage you need to create a webpage that can use server side scripting such as a PHP page or an ASP page. You also need a database, most types are supported depending how your webserver is configured.

Web pages are connected to web pages by using 'Datalinks'. The types of datalinks vary, for example, Microsoft Servers use ADO, ADO stands for ActiveX Data Object. A data link basically allows the contents of a database to be displayed in a webpage.

The exact information that is taken from the database depends on the 'Query', this a statement sent to a database telling it which records you wish to see. 'Queries are written in SQL, SQL stands for Structured Query Language.

Example Database Search

Use this form to search a simple Microsoft Access Database that contains details of Library Books. Eg. Enter 'Drawing' to find books about drawing.

Useful Links

http://www.adobe.com/ - Information about Adobe products including Photoshop

http://www.jpeg.org/ - Official site of the Joint Photographic Experts Group