外文翻译---关系数据库的结构

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1、 共 11 页 第 1 页 装 订 线 附录二：英汉翻译 一、英文原文 Structure of the Relational database Database System ConceptsPart1: Relational Databases The relational model is the basis for any relational database management system (RDBMS).A relational model has three core components: a collection of objects or relations, ope

2、rators that act on the objects or relations, and data integrity methods. In other words, it has a place to store the data, a way to create and retrieve the data, and a way to make sure that the data is logically consistent. A relational database uses relations, or two-dimensional tables, to store th

3、e information needed to support a business. Lets go over the basic components of a traditional relational database system and look at how a relational database is designed. Once you have a solid understanding of what rows, columns, tables, and relationships are, youll be well on your way to leveragi

4、ng the power of a relational database. Tables, Row, and Columns A table in a relational database, alternatively known as a relation, is a two-dimensional structure used to hold related information. A database consists of one or more related tables. Note: Dont confuse a relation with relationships. A

5、 relation is essentially a table, and a relationship is a way to correlate, join, or associate two tables. A row in a table is a collection or instance of one thing, such as one employee or one line item on an invoice. A column contains all the information of a single type, and the piece of data at

6、the intersection of a row and a column, a field, is the smallest piece of information that can be retrieved with the databases query language. For example, a table with information about employees might have a column called LAST_NAME that contains all of the employees last names. Data is retrieved from a table by filtering on both the row and the column. Primary Keys, Datatypes, and Foreign Keys The examples through