Oracle8.0 is an object relational database because it is non-pure object-oriented database, which is also a database, representing the combination of both.
The following reasons can make everyone believe that object-oriented methods will become mainstream
1: Object Database The current relational database of the user is compatible because the user can transplant the current relational database and app to Oracle8i without rewriting.
2: The current object database supports the specific query of SQL database standards. One of the reasons for the rapid acceptance of relational databases in the past is that the ability of special queries can be created. Now the object database has been provided to the standard SQL tool interface. Means easily transition from the relational database to the object database.
3: The combination of object-oriented and relationship expression is deformed in Oracle8i, more powerful than individual relationships or object-oriented expression. This makes it easier to design a compact and efficient database.
4: The object relational database is a database of the relationship between energy storage, data, and data behavior (ie, it interacts with other data). It does not just stay at the low level of processing data, and rising to the hierarchy of the object wrapped with the data.
The following will learn object-oriented basic concepts, but it is biased to objects for the database:
Object: It is a software representation of the real world entity, consisting of attributes and operations.
Class (Class): You can return multiple objects similar to each other and attributes. Class is an object template. Objects contain flesh-meat entities for classes.
Encapsulation: Indicates that the data is bound to a specific object, making it accessible to the action provided or accepted by the object (this can avoid illegal access). Packages means that each object in the database has a clearly defined interface.
Data Trigger: The relational database has a package form, but it does not have the ability to be a tool for providing package functions, because the use of excess database triggers will reduce the performance of the entire database.
Extensibility: It is an object-oriented database to add new objects and its behavior without affecting other objects and applications.
Inheritance: A code shared form. Subclasses can have data and behaviors of the parent class. It is an ability to create a new class for an object as a particularly class.
Polymorphism: It is a function of different reactions to the same message. The same object is made different reactions based on the information provided, and can understand the context of input information.
