Java Reference
In-Depth Information
Object state
Before we think about state of objects, let us first understand the fundamental tasks involved
in database programming. I have provided database programming aspects in next section in
this chapter but thinking about databases is involved when we speak about object states. In
database programming, a user can insert, delete or change some information residing per-
manently inside a database. For doing any of these operations, a business logic layer of
the computer application takes user requests and does the requested changes in the data-
base. During this data processing, the variables defined in the business logic hold some data
(provided by the user) and then process the data to convert it so that data can be inserted,
deleted or modified in the database.
Figure: 1.13: Data taken from user screen being converted into database format by business
logic layer
Consider Figure 1.13. I have provided a simple schema to understand what happens when
a user provides some data and wants the data to be saved or modified in the database. The
business logic performs the task of user request through some written code. This code con-
verts user inputs and then does some addition or modification in the database. For perform-
