Using Caché Objects - InterSystems Documentation

2
Object-Oriented Database
Development
The use of object-oriented programming is widespread and growing. Most modern user
interface code is object based and a large amount of new business logic is also being implemented
as objects. Where there is a lag is within the database layer of applications. Most
databases rely on older methodologies (such as the ISAM and relational models). Caché
brings the power of object-oriented programming to the database.
In this chapter we will briefly discuss some of the key concepts of object-oriented programming
and how they relate to database application development.
2.1 Classes and Objects
A class is a template that describes the data and behavior of a specific entity within an
application. For example, your application may define a Car class that specifies the characteristics
shared by all cars within the application.
An object is a specific instance of a class. For example, a “1972 Dodge Dart” is a specific
instance of a Car.
Objects may exist in the memory of a specific process or session (similar to variables) where
they can be manipulated (data values changed, methods invoked). Objects can also be stored
in and retrieved from a database.
Using Caché Objects 9