Develop Your First Java Application in 20 Minutes › Project Management Application

Project Management Application

In the following sections, you create a simple project management application. In this sample, a project consists of a group of tasks, and each task has one employee assigned to it. The model contains three entities: Project, Task, and Employee. To save time, the Employee entity is already defined for you.

Here is an entity-relationship diagram of the application created in this chapter. You will draw a diagram like this later.

If you have worked with entity-relationship diagrams before, you can observe the following:

• A project can have more than one task, but a task can only belong to one project.
• A task is owned by a project, which means that if you delete a project, you want all of its tasks deleted too.
• Employees are assigned to tasks—one employee can be assigned to more than one task, but each task can only have one employee assigned to it.
• An employee is not dependent on any particular task, which means that if you delete a task, you do not necessarily want to delete the employee record too.

You can see all of this without having to look at any code. This diagram shows useful information, which CA Plex uses to generate the application.

For the purpose of this sample application, this model is very basic. If you have developed real project management systems before, you may find parts of the model that you would design differently.