Wisermove.co.uk is a good example of a Web site requiring a database back end. The business concept is straightforward;   house owners register their property for a small fee, and potential purchasers search the database for details matching their requirements.

Talking Webs were commissioned to design and develop the visual elements of the site, and asked me to handle the database side. SQL Server 7 was eventually selected as the database engine, to ensure that the site can cope with high traffic levels as it grows. The Web interface is provided by VBScript in ASP.

Database design for Web applications presents a very different set of problems compared to conventional LAN systems. The property registration process must be robust and very user friendly, because the sellers input their own details, yet the property presentation must be professional and reasonably consistent. The form is designed to avoid the common complaint that input is easily lost and has to be repeated. So long as the seller notes the property reference (generated automatically) and the password they choose (or optionally generated by the system), they can very easily add or amend all other details at any time.

The search logic required the most careful design, to provide a good compromise between relevancy and ease of criteria selection. The automated emails are another key feature. Buyers can save their searches to receive details of new properties as soon as their details are published. Property details are only made visible (without using the seller’s password) once paid for and published using the password protected secure administrative pages. Here the digital photos may be uploaded, and an on-line credit card payment facility using Netbanx or Worldpay is planned.