Database Reference
In-Depth Information
on the important job of writing the code that makes you (or your company)
money—namely, the business logic.
Figure 9.1
shows where SDN fits within your broader
application.
Figure 9.1. Overview of where SDN fits within your broader application
In computer software, the requirement to read data from disk, and transform it into
application-specific data structures, then write it back out again is very common. In the
very early days of Java/RDBMS (relational database management system) projects, many
developers would handcraft their own persistence-mapping logic, using, for example, low-
level frameworks such as JDBC to directly interact with databases to create and populate
