Live ORACLE

PL/SQL supports object-oriented programming through object types. An object type encapsulates a data structure along with the functions and procedures needed to manipulate the data. The variables that form the data structure are known as attributes. The functions and procedures that manipulate the attributes are known as methods.

Object types reduce complexity by breaking down a large system into logical entities. This lets you create software components that are modular, maintainable, and reusable. Object-type definitions, and the code for the methods, are stored in the database. Instances of these object types can be stored in tables or used as variables inside PL/SQL code.

This Code shows an object type definition for a bank account :-

CREATE OR REPLACE TYPE bank_account AS OBJECT (
acct_number NUMBER(5),
balance NUMBER,
status VARCHAR2(10),
MEMBER PROCEDURE open (SELF IN OUT NOCOPY bank_account, amount IN NUMBER),
MEMBER PROCEDURE close (SELF IN OUT NOCOPY bank_account, num IN NUMBER, amount OUT NUMBER),
MEMBER PROCEDURE deposit (SELF IN OUT NOCOPY bank_account, num IN NUMBER, amount IN NUMBER),
MEMBER PROCEDURE withdraw (SELF IN OUT NOCOPY bank_account, num IN NUMBER, amount IN NUMBER),
MEMBER FUNCTION curr_bal (num IN NUMBER) RETURN NUMBER );
/

Defining an Object Type