Chapter 11 Database Management 11.1 Overview Relational data bases are used where associations among files or records cannot be expressed by links; a simple flat list becomes one table, or "relation", and multiple relations can be mathematically associated to yield desired information. Object-oriented databases store and manipulate more complex data structures, called objects", which are organized into hierarchical classes that may inherit properties from classes higher in the chain; this data base structure is the most flexible and adaptable 当文件或记录间的关系不能用链表达时,使用关系型数据库。 个表或一个“关系”,就是一个简单的非结构列表。多个关系可 通过数学关系提供所需信息。面向对象的数据库存储并处理更复 杂的称为对象的数据结构,可组织成有层次的类,其中的每个类 可以继承层次链中更高一级类的特性,这种数据库结构最灵活 最具适应性。 《什第机专出美语 18Chapter 11 Database Management 计算机专业英语 11-8 Relational databases are used where associations among files or records cannot be expressed by links; a simple flat list becomes one table, or “relation”, and multiple relations can be mathematically associated to yield desired information. Object-oriented databases store and manipulate more complex data structures, called “objects”, which are organized into hierarchical classes that may inherit properties from classes higher in the chain; this database structure is the most flexible and adaptable. 当文件或记录间的关系不能用链表达时，使用关系型数据库。一 个表或一个“关系” ，就是一个简单的非结构列表。多个关系可 通过数学关系提供所需信息。面向对象的数据库存储并处理更复 杂的称为对象的数据结构，可组织成有层次的类，其中的每个类 可以继承层次链中更高一级类的特性，这种数据库结构最灵活， 最具适应性。 11.1 Overview