5. Data Definition

Chapter 5. Data Definition

第5章.数据定义

This chapter covers how one creates the database structures that will hold one's data. In a relational  database, the raw data is stored in tables, so the majority of this chapter is devoted to explaining how  tables are created and modified and what features are available to control what data is stored in the  tables. Subsequently, we discuss how tables can be organized into schemas, and how privileges can  be assigned to tables. Finally, we will briefly look at other features that affect the data storage, such  as inheritance, table partitioning, views, functions, and triggers.

该节讲述如何创建保存数据的数据库结构。在关系型数据库中，行数据保存在表中，所以本章的要点是解释如何创建、修改表，及有哪些特性可以控制表中存储什么样的数据。接下来，会讨论表在模式中的组织，以及如何为表分配权限。最后，将会简单介绍下影响数据存储的其他特性，例如继承，表分区，视图，函数和触发器。