Data Modeling and Analysis - McGraw Hill Higher ：麦格劳山更高的数据建模与分析.pptVIP

下载本文档

8
0
约1.48万字
约 52页
2017-12-23 发布于江西
举报
版权申诉

Data Modeling and Analysis - McGraw Hill Higher ：麦格劳山更高的数据建模与分析.ppt

1、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。。
2、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。
3、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)。
4、该文档为VIP文档，如果想要下载，成为VIP会员后，下载免费。
5、成为VIP后，下载本文档将扣除1次下载权益。下载后，不支持退款、换文档。如有疑问请联系我们。
6、成为VIP后，您将拥有八大权益，权益包括：VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
7、VIP文档为合作方或网友上传，每下载1次，网站将根据用户上传文档的质量评分、类型等，对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档

Data Modeling and Analysis - McGraw Hill Higher ：麦格劳山更高的数据建模与分析

Chapter 8 Data Modeling and Analysis Objectives Define data modeling and explain its benefits. Recognize and understand the basic concepts and constructs of a data model. Read and interpret an entity relationship data model. Explain when data models are constructed during a project and where the models are stored. Discover entities and relationships. Construct an entity-relationship context diagram. Discover or invent keys for entities and construct a key-based diagram. Construct a fully attributed entity relationship diagram and describe data structures and attributes to the repository. Normalize a logical data model to remove impurities that can make a database unstable, inflexible, and nonscalable. Describe a useful tool for mapping data requirements to business operating locations. Data Modeling Data modeling – a technique for organizing and documenting a system’s data. Sometimes called database modeling. Entity relationship diagram (ERD) – a data model utilizing several notations to depict data in terms of the entities and relationships described by that data. Sample Entity Relationship Diagram (ERD) Data Modeling Concepts: Entity Entity – a class of persons, places, objects, events, or concepts about which we need to capture and store data. Named by a singular noun Data Modeling Concepts: Entity Entity instance – a single occurrence of an entity. Data Modeling Concepts: Attributes Attribute – a descriptive property or characteristic of an entity. Synonyms include element, property, and field. Just as a physical student can have attributes, such as hair color, height, etc., data entity has data attributes Compound attribute – an attribute that consists of other attributes. Synonyms in different data modeling languages are numerous: concatenated attribute, composite attribute, and data structure. Data Modeling Concepts: Data Type Data type – a property of an attribute that identifies what type of data can be stored in that attribute. Data Modeling Conce