[工学]数据库系统原理英文-4-11.ppt

  1. 1、本文档共71页,可阅读全部内容。
  2. 2、有哪些信誉好的足球投注网站(book118)网站文档一经付费(服务费),不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
  3. 3、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。如您付费,意味着您自己接受本站规则且自行承担风险,本站不退款、不进行额外附加服务;查看《如何避免下载的几个坑》。如果您已付费下载过本站文档,您可以点击 这里二次下载
  4. 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“版权申诉”(推荐),也可以打举报电话:400-050-0827(电话支持时间:9:00-18:30)。
查看更多
[工学]数据库系统原理英文-4-11

March 2011 Database System Concepts - Chapter4 Advanced SQL - PART 2 RELATIONAL DATABASES Chapter 4 Advanced SQL Integrity constraints in SQL §4.1-4.2 Security in SQL (§4.3) authorization, grant/revoke Embedded and dynamic SQL §4.4-4.5 4.1.1 Built-in Data Types in SQL In addition to the basic data types, e.g. char(n), varchar(n), int, smallint, numeric(p, d), real, double precision, float(n), described in §3.2, the other built-in data types include date: Dates, containing a (4 digit) year, month and date e.g. date ‘2005-7-27 time: Time of day, in hours, minutes and seconds e.g. time ‘09:00:30.75 timestamp: date plus time of day e.g. timestamp ‘2005-7-27 09:00:30.75’ interval: period of time e.g. interval ‘1’ day Subtracting a date/time/timestamp value from another gives an interval value interval values can be added to date/time/timestamp values Values of individual fields can be extracted from date/time/timestamp e.g. extract (year from r.starttime) We can cast /convert string types to date/time/timestamp e.g. cast string-valued-expression as date e.g. cast string-valued-expression as time The create type clause can be used to define new user-defined types e.g. create type Dollars as numeric (12,2) final The create domain clause can be used to define new user-defined domains e.g. create domain person_name char(20) not null 4.1.3 Large-Object Types Large objects (photos, videos, CAD files, etc.) are stored as a large object blob: binary large object the object is a large collection of uninterpreted binary data, whose interpretation is left to an application outside of the database system clob: character large object the object is a large collection of character data When a query returns a large object, a pointer is returned rather than the large object itself. 4.1.3 Large-Object Types (cont.) E.g. book_view clob(10KB) image blob(10MB) movie blob(2GB) 4.1.4 Schemas, Catalogs, and Environments How to name the

文档评论(0)

qiwqpu54 + 关注
实名认证
内容提供者

该用户很懒,什么也没介绍

1亿VIP精品文档

相关文档