关系数据库的结构及数据库管理系统大学毕业论文外文文献翻译及原文.docx

毕业设计（论文） 外文文献翻译 文献、资料中文题目： 1.关系数据库的结构2.数据库管理系统 文献、资料英文题目：〔.Structure of the Relational database2.Database Man ageme nt System 文献、资料来源： 文献、资料发表（出版）日期： 院（部）: 专 业： 班 级： 姓 名： 学 号： 指导教师： 翻译日期： 2017.02.14 原文: Structure of the Relational database —《Database System Concepts 》Parti: Relational Databases The relational model is the basis for any relational database man ageme nt system (RDBMS).A relati onal model has three core components: a collection of objects or relations, operators 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 con siste nt. A relational database uses relations, or two -dimensional tables, to store the in formati on n eeded to support a bus in ess. Lets go over the basic comp onents of a traditi onal relati onal database system and look at how a relational database is designed. Once you have a solid un dersta nding of what rows, colu mns, tables, and relati on ships are, youll be well on your way to leveraging the power of a relational database. Tables, Row, and Columns A table in a relati onal database, alter natively known as a relatio n, is a two-dimensional structure used to hold related information. A database con sists of one or more related tables. Note: Dont con fuse a relatio n with relati on ships. A relati on is esse ntially a table, and a relati on ship is a way to correlate, join, or associate two tables. A row in a table is a collectio n or in sta nee of one thi ng, such as one employee or one line item on an invoice. A column contains all the in formatio n of a sin gle type, and the piece of data at the in tersect ion of a row and a colu mn, a field, is the smallest piece of in formatio n that can be retrieved with the databases query Ianguage. For example, a table with in formati on about employees might have a colu mn called LAST_NAME that contains all of the employees