Nowadays, we can easily access a remote database as well as a local database with HTML forms. Although implementing a database application with HTML forms is much simpler than implementing it with a proprietary graphical user Interface system, HTML forms and CGI programs still must be coded. We implemented a software tool that automatically generates the SQL statements that create a database for an application, the forms that are used as a user interface, and the Java servlets that retrieve the data requested through the forms. The database tables to be treated and the forms to be generated are determined by the class diagram for the application. Our software tool, which we call WebSiteGen, thus simplifies the implementation of a Web-based database application.