'Weak entity sets' diaporamas de présentation

Entity-Relationship Model

Entity-Relationship Model. E-R Diagrams Class hierarchies Weak entity sets. Purpose of E/R Model. The E/R model allows us to sketch the design of a database informally. Designs are pictures called entity-relationship diagrams .

1k views • 68 slides

Chapter 4

Chapter 4. Notes. Entity-Relationship Model. E/R Diagrams Weak Entity Sets Converting E/R Diagrams to Relations. Purpose of E/R Model. The E/R model allows us to sketch database schema designs. Includes some constraints, but not operations.

748 views • 61 slides

Chapter 2: Entity-Relationship Model

Chapter 2: Entity-Relationship Model. Entity Sets Relationship Sets Design Issues Mapping Constraints Keys E-R Diagram Extended E-R Features Design of an E-R Database Schema Reduction of an E-R Schema to Tables. Entity Sets. A database can be modeled as: a collection of entities,

819 views • 54 slides

Entity-Relationship Model

Entity-Relationship Model. Diagrams Class hierarchies Weak entity sets. Purpose of E/R Model. The E/R model allows us to sketch database designs. Kinds of data and how they connect. Not how data changes. Designs are pictures called entity-relationship diagrams .

686 views • 54 slides

Entity-Relationship Model

Entity-Relationship Model. Lecture 5. Database Modeling and Implementation Process. Ideas . ER Design . Relational Schema. Relational DBMS Implementation. ER Model Components. Entity Sets Attributes Relationships. ER Model.

1.32k views • 53 slides

Entity-Relationship Model

Entity-Relationship Model. Outline. Entity Sets Relationship Sets Design Issues Mapping Constraints Keys E-R Diagram Extended E-R Features Design of an E-R Database Schema Reduction of an E-R Schema to Tables. Entity Sets.

944 views • 52 slides

Conceptual Data Models Chapter 7

Conceptual Data Models Chapter 7. Conceptual Data Model . Requirement collection/analysis results in well-formed requirements Can be used to create conceptual data model diagram Useful in understanding DB Used to map to DB model of DBMS Examples are: ER/EER model UML.

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609 views • 42 slides

Chapter 2: Entity-Relationship Model

Chapter 2: Entity-Relationship Model. Entity Sets Relationship Sets Mapping Constraints Keys Participation Constraints E-R Diagram Extended E-R Features Design of an E-R Database Schema Reduction of an E-R Schema to Tables Objective: conceptual DB design using ER diagrams.

598 views • 41 slides

Functional Dependencies and Relational Schema Design

1.24k views • 36 slides

E-R Model

E-R Model. A database can be modeled as: a collection of entities, relationship among entities. An entity is an object that exists and is distinguishable from other objects. Example: specific person, company, event, plant Entities have attributes

545 views • 35 slides

COP4710 Database Systems

COP4710 Database Systems. E-R Model. Fall 2013. Why should we study this?. Key Steps in Building DB Applications. Step 0: pick an application domain We will talk about this later Step 1: conceptual design Discuss with your team mate what to model in the application domain

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Translating from ER to Relationship Schema

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Weak Entity Sets

Weak Entity Sets. An entity set that does not have a primary key is referred to as a weak entity set . The existence of a weak entity set depends on the existence of a identifying(or owner) entity set

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Relational Database

Relational Database. Relational Database. Relational database : a set of relations Relation : made up of 2 parts: Schema : specifies the name of relations, plus name and type of each column.

429 views • 23 slides

Department of Computer and Information Science, School of Science, IUPUI

Department of Computer and Information Science, School of Science, IUPUI. Data Modeling Attributes, Roles, Subclasses, Keys and Weak Entities. Dale Roberts, Lecturer Computer Science, IUPUI E-mail: droberts@cs.iupui.edu. Attributes on Relationships.

342 views • 19 slides

Department of Computer and Information Science, School of Science, IUPUI

Department of Computer and Information Science, School of Science, IUPUI. Data Modeling Attributes, Roles, Subclasses, Keys and Weak Entities. Dale Roberts, Lecturer Computer Science, IUPUI E-mail: droberts@cs.iupui.edu. Attributes on Relationships.

317 views • 19 slides

Transformation of E/R Diagram to Relation

Transformation of E/R Diagram to Relation. Transformation of E/R Diagram to Relation. Primary keys allow entity sets and relationship sets to be expressed uniformly as relations E/R diagram ? collection of tables For each entity set and each relationship set there is a unique table.

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Translating E/R Diagrams into Relational Schemas

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Amity School of Engineering & Technology B. Tech. (CSE/IT), III Semester

Amity School of Engineering & Technology B. Tech. (CSE/IT), III Semester Database Management Systems Jitendra Rajpurohit.

238 views • 11 slides