Size: px
Start display at page:

Download ""

Transcription

1 0. Database Systems 1.1 Introduction to DBMS Information is one of the most valuable resources in this information age! How do we effectively and efficiently manage this information? - How does Wal-Mart manage its 200 TB data warehouse? - What is the database technology behind ebay's website? - How do you build an Oracle 10g, IBM DB2 or Microsoft SQL Server database? Relational Database Management Systems: Dominant data management paradigm today 10 Billion dollar a year industry (in the U.S. only): You will see this in the job market! 0.1 What the subject is about This course covers the fundamental concepts in database systems: Organization of data Efficient retrieval of data Reliable storage of data Maintaining consistent data Not surprisingly, all these topics are interrelated. 1.0 What is a Database System (DBS)? A Database (DB) is a very large, integrated collection of data designed to meet the information needs of an organization. A DB models a real world enterprise. Entities: e.g. students, courses... A Database Management System (DBMS) is a software package designed to store and manages databases. Allows the user to define the database through a Data Definition Language (DDL). Allows users to insert, update, delete, and retrieve data from the database through a Data Manipulation Language (DML). Provides controlled access to the database. Database System = DBMS + Data Why don't us program up" databases when we need them? For simple and small databases this is often the best solution: Flat files and grep get us a long way. We run into problems when The structure is complicated (more than a simple table) The database gets large Many people want to use it simultaneously Actors in the Database Environment Data and Database Administrators / Database Designers Designs the logical/physical schemas Handles Security and authorization Crash Recovery Database tuning as needs evolve Application Programmers: Provide the required functionality to the end-users End-Users: Clients for the database Naive users: unaware of the DBMS Sophisticated users: Familiar with the structure of the database and the facilities offered by the DBMS. Relationships: e.g. Rashmi is taking CS G DBMS Module 1 1

2 1.1.2 Advantages and Disadvantages of DBMS Data Model Advantages Control of Data Redundancy Data Consistency Sharing of Data Improved Data Integrity and Security Increased Concurrency Disadvantages: Complexity Size Cost of DBMS Additional Hardware Costs Performance Higher Impact of Failure Database architecture It is common to describe databases in two ways: The logical level: What users see, i.e. the program or query language interface. - It is traditional to split the logical level into two components: A data model describes conceptual structuring of data stored in database. - Example: Data is set of records, each with ID, name, address, and courses. - Example: Data is a graph where nodes represent proteins and edges represent chemical bonds between proteins. Data model provides a description of the database structure including: The data The relationships within the data The constraints on the data Different representation methods: Entity-Relationship Model Relational Model Object-Oriented Model Object Relational Model Semistructured Data Model Schema & Instance Database Schema describes how data is to be structured. It is a description of the logical view of database. A common tool used to design schema is an entityrelationship diagram. - defined during creation of the database - rarely change - Conceptual level: overall database design - Views that various users get to see. The physical level: How files are organized, what indexing mechanisms are used. Database instance: The data stored in the database at a given moment. - rapidly change - updated continuously DBMS Module 1 2

3 1.1.6 Data independence DBMS Interfaces Data independence: one of the most important benefits of DBMS A user of a relational database system should be able to use SQL to query the database without knowing about how precisely data is stored. e.g.: SELECT When, Where FROM Calendar WHERE Who = "Bill" We distinguish between two kinds of data independence: Logical data independence protects the user from changes in the logical structure of the data - could completely reorganize the calendar "schema without changing how I query it. Physical data independence protects the user from changes in the physical structure of data: could add an index on Who without changing how the user would write the query, but the query would execute faster (query optimization) Database Languages Data Definition Language (DDL): Allows the user to define the database conceptual schema Storage Definition Language (SDL), is used to specify the internal schema Data Manipulation Language (DML): Allows users to insert, update, delete, and retrieve data from the database through a Query. Menu-Based Interface Form-Based Interface Graphical User Interface - utilize both Menu & Form Natural Language Interface - These interfaces accept requests written in English (or similar) and attempt to understand them. Interfaces for Parametric Users - Parametric users (e.g. : bank tellers) often have a small set of operations that they must perform repeatedly Interfaces for the DBA (DB Administrator) - Most database systems contain privileged commands that can be used only by the DBA s staff. DBMS Module 1 3

4 1.2 Entity-Relationship Model Attributes: An Example First introduced in the mid 1970's by Chen as an improvement to the relational model. The Entity-Relationship (E/R) model allows us to draw diagrams of database designs. Represent different types of data and how they relate to each other. The design is a drawing called the entityrelationship diagram. The Entity-Relationship model is an example of what is called a semantic model Description of conceptual and external levels of data Independent of the internal and physical aspects Ideas E/R Design Relational Schema Relational DBMS Entity - Entity Set - Attributes An Entity is an abstract object of some sort. Examples: Banking system: Customer, Account, Loan. Airline system: Aircraft, Passenger, Flight, Airport. An Entity set is a collection of similar entities. Entities have attributes. An attribute is a property of the entities in an entity set. In an E/R diagram: A rectangle represents an entity set An oval represents an attribute A line connects an entity set (rectangle) to an attribute (oval) What appears to be an attribute to one designer may be an entity to another Attributes: Domain and Values Attributes have a value set or domain (set of possible values). - Null values: Sometimes the value of an attribute is unknown at the present time or undefined for a particular instance. Composite Attributes: can be decomposed into smaller elements. - Example: Address can be broken down into street, city, state, and zip. Multivalued Attributes: have multiple values for an entity instance, e.g. student with more than one address. They are represented with a double oval. Derived Attributes: whose value can be calculated when needed. - Example: Age may be determined from the current date and the date of birth. DBMS Module 1 4

5 Attributes in ER-Diagram Keys Multivalued Attribute: Double oval around the attribute's name Composite Attribute: Writing the name in an oval and then drawing ovals for the individual components which are connected by lines to the composite attribute's oval Derived Attribute: Dashed oval around the attribute's name Entity Identification The process of identifying entities is one of the most important steps in developing a data model. Some guidelines: An informal questioning approach: the analyst asks targeted questions to determine what information is necessary and whether or not that information is recorded within the system. Face to face discussions with user: the nouns should be recorded. The existing documentation often contains clues. Every fact that is required to support the business is almost certainly an attribute. In turn each of these attributes will belong to an entity. If no parent" entity can be found for one or more of these low level facts, then this indicates that your entity search is incomplete. Entity identification can continue once the drawing of the data model diagram has begun Each entity occurrence can be uniquely identified, by using an attribute or a combination of attributes as a key. A Super Key is the attribute (or group of attributes) that serve to uniquely identify each entity occurrence. Consider the following problem: the name and address of an individual were used as the super key for identifying the patients within a hospital. Take the example of a patient called Sameer Muhammad living in Calicut City. He has a son also called Sameer Muhammad living at the same address. Name and Address would not necessarily provide a unique identifier and confusion could easily arise. In a hospital system patients each have a Patient Number as their super key. If two or more data items are used as the unique identifier, then this represents a Compound Key. - Example: a compound key used to identify a book could be Title" together with Author". A Candidate Key is a super key such that no proper subset of its attributes is itself a super key. An entity set might have several candidate keys. - Example: A book could be identified, either by Title" together with Author" or by the widely used unique identifier for books - the ISBN number. The Primary Key is the candidate key actually chosen. DBMS Module 1 5

6 1.2.3 Relationships Entities are often linked by associations or relationships. Recursive Relationships A Recursive Relationship is a relationship that associates an entity type with itself. A Relationship is a connection between two or more entity sets. In an E/R diagram a diamond represents a relationship a line connects the relationship to each entity set. Or Alternative representation of relationships: Relationship link phrase should be a short description of the nature of the relationship. It is always read clockwise with respect to the entities that it links. - Example: Manager is responsible for department" and Department is responsibility of manager". Ternary Relationships A relationship set need not be an association of precisely two entities; it can involve three or more when applicable. A relationship that involves three entities is called ternary relationship. Relationship Cardinality One-to-one relationship: Each manager is responsible for only one department and each department is the responsibility of only one manager. One-to-many relationship: Each company employs one or more employees, but each employee is employed by only one company. Many-to-many relationship: Each lecturer teaches one or more courses and each course is taught by one or more lecturers Identifying Relationships In order to identify the degree of the relationship between the entities X and Y the following two questions need to be asked. Question 1: Can an occurrence of X be associated with more than one occurrence of Y? Question 2: Can an occurrence of Y be associated with more than one occurrence of X? Four possible outcomes: Question 1 Question 2 Option 1 YES NO Option 2 No YES Option 3 YES YES Option 4 NO NO Option 1 and Option 2: A one-to-many relationship has been identified. Option 3: A many-to-many relationship has been identified. Option 4: A one-to-one link has been identified. DBMS Module 1 6

7 Relationship Participation The final property of the relationship statement is the total and partial participation. A solid line shows that an entity occurrence must be associated with each occurrence of the other entity. - Example: Each passenger must possess a ticket, and each ticket must belong to a passenger. A dotted line shows that an entity occurrence may be associated with each occurrence of the other entity. - Example: Each book may be borrowed by a borrower, and each borrower must borrow one or more books Weak Entities A Weak Entity is an entity that cannot be uniquely identified by its own attributes alone. A weak entity can be identified uniquely only by considering another entity. Example: Each book has several editions, and certainly it is nonsense to speak about an edition if this does not happen in the context of a specific book ER Diagram Example - Small Conference We need to keep track of authors that submit papers to the conference. An author should be identified uniquely and information such as his name (first, middle and last name) and research specialization should be recorded. We need to keep track of the papers submitted to the conference. A research paper is identified by its author, title, and date. One author can submit one or more papers to the conference and some papers are submitted by more than one author. Each paper is related to one or more research topics. We need to keep track of the research topics that the conference has covered. A research topic should be uniquely identified. The founder(s) and description of each topic should also be recorded. Each author participating in the conference has an account through which he can access all conference-related material. An account is identified by a unique username. The password, issue date and validity period of an account should also be recorded. A weak entity is depicted in the ERD by drawing a double rectangle around the entity and making the relationship diamond a double diamond. DBMS Module 1 7

8 Summary of ER diagram notation ERD Example - Small Conference DBMS Module 1 8

9 EER Diagrams 1.3 Enhanced Entity-Relationship (EER) Model The basic concepts of ER modelling are not powerful enough for some complex applications. We require some additional modelling concepts to represent more semantic information than the standard ER model. The Enhanced Entity-Relationship (EER) model extends the ER model to include various types of abstraction and to express constraints more clearly. Additional concepts in EER-Model: Specialization Generalization Categorization Inheritance Some of the concepts correspond to concepts in objectoriented design Superclass and Subclass Example: Staff may be grouped into Manager, Sales personnel, Finance Personnel, and Secretary. - Each of these groupings is a subset of Staff entities. - Each of these groupings is called subclass of Staff. - Staff is the superclass for each of these subclasses. Superclass: an entity type that includes distinct subclasses that requires to be represented in a data model. Subclass: an entity type that has a distinct role and is also a member of a superclass Inheritance An entity that is a member of a subclass inherits all attributes of the entity as a member of the super class. A subclass may optionally have distinct local attributes. A subclass also inherits all relationships. Sometimes the relationship superclass and subclass is referred to as an isa relationship Specialization Specialization is the process of defining a set of subclasses of a superclass. The set of subclasses is based upon some distinguishing characteristics of the entities of the superclass. Specialization is represented in EERdiagrams by A specialization circle connected by a line to a superclass. Each subclass is connected to the circle by a line having an inheritance symbol, i.e. a subset symbol or cup, with the open side facing the super class. Example of Specialization DBMS Module 1 9

10 EER Diagrams Generalization Generalization is the reverse of the specialization process. Several classes with common features are generalized into a superclass. - Example: Students and faculty both have IDs and names as attributes. The two entities can be generalized into a new superclass Person having the common attributes. The subclasses Student and Faculty would each retain their special attributes. Using generalization, we develop diagrams from the bottom up. Using specialization, we develop diagrams from the top down Constraints on Specialization and Generalization Disjointness Constraint: specifies that the subclasses of the specialization must be disjointed, i.e. an entity can be a member of at most one of the subclasses. The disjointness constraint is specified by D or O in the EER-diagram: If the constraint is satisfied, then we write a D in the specialization circle. If the constraint is not satisfied, then we have overlapping subclasses. We write an O in the circle. Example of Disjointness Completeness Constraints A specialization has also a completeness constraint, which shows whether every member of the entity set must participate in it. If every member of the superclass must belong to some subclass, we have total specialization. If some superclass members can be permitted not to belong to any subclass the specialization is partial. The completeness constraint is specified in the EER-diagram: Total specialization: double line connecting the superclass to the specialization circle Partial specialization: single line connecting the superclass to the specialization circle Example of Completeness DBMS Module 1 10

11 EER Diagrams Predicate-defined Constraints on Specialization In specialization hierarchies, it is possible to identify the subclass that an entity belongs to by checking a specific condition or predicate for each subclass. Example of Attribute-defined Specialization The specialization is called predicate-defined specialization. For the predicate-defined specialization: On an EER-diagram, we can write the defining predicate on the line from the specialization circle to the subclass. If the predicate uses the same attribute for all subclasses, we call the specialization an attribute-defined specialization. For the attribute-defined specialization: On an EERdiagram, we indicate the defining attribute on the line from the circle to the superclass, and the distinguishing value for each subclass on the line from the subclass to the circle. Specializations that are not predicate-defined are called user-defined specialization. Example of Predicate-defined Specialization DBMS Module 1 11

12 EER Diagrams Hierarchies and Lattices A subclass may itself have further subclasses. This forms a hierarchy or a lattice. Hierarchy has a constraint that every subclass has only one superclass: Single inheritance. In a lattice, a subclass can have more than one superclass: Multiple inheritance. A subclass with more than one superclass is called shared subclass. In a lattice or hierarchy, a subclass inherits attributes not only of its direct subclass, but also of all its predecessor superclasses. Example of Hierarchy Example of Lattice Categories: Union A shared subclass is a subclass having more than one superclass. A shared subclass inherits all attributes from all the superclasses. In some cases, we need to model a single superclass/subclass relationship with more than one superclass. In other words, the subclass should be related to one of the collection, called a union or category. An instance of the subclass inherits the attributes of only one of the superclass depending on which member of the union that it belongs to. - Example: A database for vehicle registration: vehicle owner can be a person, a bank, or a company. Category (subclass): Owner is a subset of the union of the three superclasses Company, Bank, and Person. A category member must exist in a least one of its superclasses. In an EER-diagram: we represent a category by a union circle connecting the subclass with its superclasses. Example of Union DBMS Module 1 12

Chapter 2: Entity-Relationship Model

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

More information

Chapter 2: Entity-Relationship Model. Entity Sets. Entity Sets customer and loan. Attributes. Relationship Sets. A database can be modeled as:

Chapter 2: Entity-Relationship Model. Entity Sets. Entity Sets customer and loan. Attributes. Relationship Sets. A database can be modeled as: Chapter 2: Entity-Relationship Model Entity Sets 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

More information

Chapter 4. Enhanced Entity- Relationship Modeling. Enhanced-ER (EER) Model Concepts. Subclasses and Superclasses (1)

Chapter 4. Enhanced Entity- Relationship Modeling. Enhanced-ER (EER) Model Concepts. Subclasses and Superclasses (1) Chapter 4 Enhanced Entity- Relationship Modeling Enhanced-ER (EER) Model Concepts Includes all modeling concepts of basic ER Additional concepts: subclasses/superclasses, specialization/generalization,

More information

Chapter 6: Entity-Relationship Model

Chapter 6: Entity-Relationship Model Chapter 6: Entity-Relationship Model Database System Concepts, 5th Ed. See www.db-book.com for conditions on re-use Chapter 6: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

COMP Instructor: Dimitris Papadias WWW page:

COMP Instructor: Dimitris Papadias WWW page: COMP 5311 Instructor: Dimitris Papadias WWW page: http://www.cse.ust.hk/~dimitris/5311/5311.html Textbook Database System Concepts, A. Silberschatz, H. Korth, and S. Sudarshan. Reference Database Management

More information

6.1 RELATIONSHIP CONCEPTS

6.1 RELATIONSHIP CONCEPTS 1 SYLLABUS 6.1 Basic Entity Relationship Concepts: Entities, Relationship, Attributes 6.2 E R Diagram symbols 6.3 Conversion of Entity Relationship Model into Relations 6.4 Problems with Enitty Relationship

More information

The Next Step: Designing DB Schema. Chapter 6: Entity-Relationship Model. The E-R Model. Identifying Entities and their Attributes.

The Next Step: Designing DB Schema. Chapter 6: Entity-Relationship Model. The E-R Model. Identifying Entities and their Attributes. Chapter 6: Entity-Relationship Model Our Story So Far: Relational Tables Databases are structured collections of organized data The Relational model is the most common data organization model The Relational

More information

Chapter 6: Entity-Relationship Model. The Next Step: Designing DB Schema. Identifying Entities and their Attributes. The E-R Model.

Chapter 6: Entity-Relationship Model. The Next Step: Designing DB Schema. Identifying Entities and their Attributes. The E-R Model. Chapter 6: Entity-Relationship Model The Next Step: Designing DB Schema Our Story So Far: Relational Tables Databases are structured collections of organized data The Relational model is the most common

More information

A database can be modeled as: + a collection of entities, + a set of relationships among entities.

A database can be modeled as: + a collection of entities, + a set of relationships among entities. The Relational Model Lecture 2 The Entity-Relationship Model and its Translation to the Relational Model Entity-Relationship (ER) Model + Entity Sets + Relationship Sets + Database Design Issues + Mapping

More information

Chapter (4) Enhanced Entity-Relationship and Object Modeling

Chapter (4) Enhanced Entity-Relationship and Object Modeling Chapter (4) Enhanced Entity-Relationship and Object Modeling Objectives Concepts of subclass and superclass and the related concepts of specialization and generalization. Concept of category, which is

More information

Chapter 6: Entity-Relationship Model

Chapter 6: Entity-Relationship Model Chapter 6: Entity-Relationship Model Database System Concepts, 5th Ed. See www.db-book.com for conditions on re-use Chapter 6: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

COIS Databases

COIS Databases Faculty of Computing and Information Technology in Rabigh COIS 342 - Databases Chapter 4 Enhanced Entity-Relationship and UML Modeling Adapted from Elmasri & Navathe by Dr Samir BOUCETTA First Semester

More information

LELCTURE 4: ENHANCED ENTITY-RELATIONSHIP MODELING (EER)

LELCTURE 4: ENHANCED ENTITY-RELATIONSHIP MODELING (EER) LELCTURE 4: ENHANCED ENTITY-RELATIONSHIP MODELING (EER) Ref. Chapter12 from Database Systems: A Practical Approach to Design, Implementation and Management. Thomas Connolly, Carolyn Begg. IS220 : D at

More information

Entity-Relationship Model

Entity-Relationship Model Entity-Relationship Model Data Models High-level or conceptual data models provide concepts that are close to the way many users perceive data, whereas low-level or physical data models provide concepts

More information

1. Considering functional dependency, one in which removal from some attributes must affect dependency is called

1. Considering functional dependency, one in which removal from some attributes must affect dependency is called Q.1 Short Questions Marks 1. Considering functional dependency, one in which removal from some attributes must affect dependency is called 01 A. full functional dependency B. partial dependency C. prime

More information

Entity Relationship Data Model. Slides by: Shree Jaswal

Entity Relationship Data Model. Slides by: Shree Jaswal Entity Relationship Data Model Slides by: Shree Jaswal Topics: Conceptual Modeling of a database, The Entity-Relationship (ER) Model, Entity Types, Entity Sets, Attributes, and Keys, Relationship Types,

More information

Entity-Relationship Modelling. Entities Attributes Relationships Mapping Cardinality Keys Reduction of an E-R Diagram to Tables

Entity-Relationship Modelling. Entities Attributes Relationships Mapping Cardinality Keys Reduction of an E-R Diagram to Tables Entity-Relationship Modelling Entities Attributes Relationships Mapping Cardinality Keys Reduction of an E-R Diagram to Tables 1 Entity Sets A enterprise can be modeled as a collection of: entities, and

More information

More on the Chen Notation

More on the Chen Notation More on the Chen Notation Reference: http://www.vertabelo.com/blog/technical-articles/chen-erd-notation Peter Chen, who developed entity-relationship modeling and published his work in 1976, was one of

More information

Conceptual Data Models for Database Design

Conceptual Data Models for Database Design Conceptual Data Models for Database Design Entity Relationship (ER) Model The most popular high-level conceptual data model is the ER model. It is frequently used for the conceptual design of database

More information

Intro to DB CHAPTER 6

Intro to DB CHAPTER 6 Intro to DB CHAPTER 6 DATABASE DESIGN &THEER E-R MODEL Chapter 6. Entity Relationship Model Design Process Modeling Constraints E-R Diagram Design Issues Weak Entity Sets Extended E-R Features Design of

More information

Represent entities and relations with diagrams

Represent entities and relations with diagrams LEARNING OBJECTIVES Define data modeling terms Describe E-R Model Identify entities and relations Represent entities and relations with diagrams WHAT IS DATA MODELING? A data model is a collection of concepts

More information

Enhanced Entity- Relationship Models (EER)

Enhanced Entity- Relationship Models (EER) Enhanced Entity- Relationship Models (EER) LECTURE 3 Dr. Philipp Leitner philipp.leitner@chalmers.se @xleitix LECTURE 3 Covers Small part of Chapter 3 Chapter 4 Please read this up until next lecture!

More information

Relational Model (cont d) & Entity Relational Model. Lecture 2

Relational Model (cont d) & Entity Relational Model. Lecture 2 Relational Model (cont d) & Entity Relational Model Lecture 2 Relational Database Operators Relational algebra Defines theoretical way of manipulating table contents using relational operators: SELECT

More information

Chapter 6: Entity-Relationship Model

Chapter 6: Entity-Relationship Model Chapter 6: Entity-Relationship Model Database System Concepts, 5th Ed. See www.db-book.com for conditions on re-use Chapter 6: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

CS 4604: Introduction to Database Management Systems. B. Aditya Prakash Lecture #5: Entity/Relational Models---Part 1

CS 4604: Introduction to Database Management Systems. B. Aditya Prakash Lecture #5: Entity/Relational Models---Part 1 CS 4604: Introduction to Database Management Systems B. Aditya Prakash Lecture #5: Entity/Relational Models---Part 1 E/R: NOT IN BOOK! IMPORTANT: Follow only lecture slides for this topic! Differences

More information

Design Process Modeling Constraints E-R Diagram Design Issues Weak Entity Sets Extended E-R Features Design of the Bank Database Reduction to

Design Process Modeling Constraints E-R Diagram Design Issues Weak Entity Sets Extended E-R Features Design of the Bank Database Reduction to Design Process Modeling Constraints E-R Diagram Design Issues Weak Entity Sets Extended E-R Features Design of the Bank Database Reduction to Relation Schemas Database Design UML A database can be modeled

More information

E-R Model. Hi! Here in this lecture we are going to discuss about the E-R Model.

E-R Model. Hi! Here in this lecture we are going to discuss about the E-R Model. E-R Model Hi! Here in this lecture we are going to discuss about the E-R Model. What is Entity-Relationship Model? The entity-relationship model is useful because, as we will soon see, it facilitates communication

More information

UNIT I. Introduction

UNIT I. Introduction UNIT I Introduction Objective To know the need for database system. To study about various data models. To understand the architecture of database system. To introduce Relational database system. Introduction

More information

Data Analysis 1. Chapter 2.1 V3.1. Napier University Dr Gordon Russell

Data Analysis 1. Chapter 2.1 V3.1. Napier University Dr Gordon Russell Data Analysis 1 Chapter 2.1 V3.1 Copyright @ Napier University Dr Gordon Russell Entity Relationship Modelling Overview Database Analysis Life Cycle Components of an Entity Relationship Diagram What is

More information

Copyright 2016 Ramez Elmasri and Shamkant B. Navathe

Copyright 2016 Ramez Elmasri and Shamkant B. Navathe CHAPTER 4 Enhanced Entity-Relationship (EER) Modeling Slide 1-2 Chapter Outline EER stands for Enhanced ER or Extended ER EER Model Concepts Includes all modeling concepts of basic ER Additional concepts:

More information

Database Systems. A Practical Approach to Design, Implementation, and Management. Database Systems. Thomas Connolly Carolyn Begg

Database Systems. A Practical Approach to Design, Implementation, and Management. Database Systems. Thomas Connolly Carolyn Begg Database Systems A Practical Approach to Design, Implementation, and Management For these Global Editions, the editorial team at Pearson has collaborated with educators across the world to address a wide

More information

Chapter 7: Entity-Relationship Model

Chapter 7: Entity-Relationship Model Chapter 7: Entity-Relationship Model Database System Concepts, 6 th Ed. See www.db-book.com for conditions on re-use Chapter 7: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

Entity Relationship Modelling

Entity Relationship Modelling Entity Relationship Modelling Overview Database Analysis Life Cycle Components of an Entity Relationship Diagram What is a relationship? Entities, attributes, and relationships in a system The degree of

More information

Chapter 7: Entity-Relationship Model

Chapter 7: Entity-Relationship Model Chapter 7: Entity-Relationship Model Database System Concepts, 6 th Ed. See www.db-book.com for conditions on re-use Chapter 7: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 7 Data Modeling with Entity Relationship Diagrams

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 7 Data Modeling with Entity Relationship Diagrams Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition Chapter 7 Data Modeling with Entity Relationship Diagrams Objectives In this chapter, students will learn: The

More information

Chapter 7: Entity-Relationship Model

Chapter 7: Entity-Relationship Model Chapter 7: Entity-Relationship Model Database System Concepts, 6 th Ed. See www.db-book.com for conditions on re-use Chapter 7: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

Chapter 2 ENTITY RELATIONSHIP MODEL

Chapter 2 ENTITY RELATIONSHIP MODEL INTRODUCTION Chapter 2 ENTITY RELATIONSHIP MODEL Data model is used to describe data, data relationship and constraints on data. A number of different data models have proposed. They can broadly be classified

More information

IS 263 Database Concepts

IS 263 Database Concepts IS 263 Database Concepts Lecture 1: Database Design Instructor: Henry Kalisti 1 Department of Computer Science and Engineering The Entity-Relationship Model? 2 Introduction to Data Modeling Semantic data

More information

Chapter 9: Relational DB Design byer/eer to Relational Mapping Relational Database Design Using ER-to- Relational Mapping Mapping EER Model

Chapter 9: Relational DB Design byer/eer to Relational Mapping Relational Database Design Using ER-to- Relational Mapping Mapping EER Model Chapter 9: Relational DB Design byer/eer to Relational Mapping Relational Database Design Using ER-to- Relational Mapping Mapping EER Model Constructs to Relations Relational Database Design by ER- and

More information

Example: specific person, company, event, plant

Example: specific person, company, event, plant 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,

More information

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 8 Data Modeling Advanced Concepts

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 8 Data Modeling Advanced Concepts Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition Chapter 8 Data Modeling Advanced Concepts Objectives In this chapter, students will learn: About the extended entity

More information

CSIT5300: Advanced Database Systems

CSIT5300: Advanced Database Systems CSIT5300: Advanced Database Systems L01: Entity Relationship (ER) Model Dr. Kenneth LEUNG Department of Computer Science and Engineering The Hong Kong University of Science and Technology Hong Kong SAR,

More information

A l Ain University Of Science and Technology

A l Ain University Of Science and Technology A l Ain University Of Science and Technology 4 Handout(4) Database Management Principles and Applications The Entity Relationship (ER) Model http://alainauh.webs.com/ 1 In this chapter, you will learn:

More information

Conceptual Data Modeling

Conceptual Data Modeling Conceptual Data odeling A data model is a way to describe the structure of the data. In models that are implemented it includes a set of operations that manipulate the data. A Data odel is a combination

More information

Chapter 6: Entity-Relationship Model. E-R Diagrams

Chapter 6: Entity-Relationship Model. E-R Diagrams Chapter 6: Entity-Relationship 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:

More information

Chapter 8: Enhanced ER Model

Chapter 8: Enhanced ER Model Chapter 8: Enhanced ER Model Subclasses, Superclasses, and Inheritance Specialization and Generalization Constraints and Characteristics of Specialization and Generalization Hierarchies Modeling of UNION

More information

Chapter 1 Chapter-1

Chapter 1 Chapter-1 Chapter 1 Chapter-1 Data: Data are the raw facts that can be obtained after some experiments or observations. Raw data is of no use until and unless we process it to find some useful information form it.

More information

Enhanced Entity-Relationship (EER) Modeling

Enhanced Entity-Relationship (EER) Modeling CHAPTER 4 Enhanced Entity-Relationship (EER) Modeling Copyright 2017 Ramez Elmasri and Shamkant B. Navathe Slide 1-2 Chapter Outline EER stands for Enhanced ER or Extended ER EER Model Concepts Includes

More information

Chapter 8 The Enhanced Entity- Relationship (EER) Model

Chapter 8 The Enhanced Entity- Relationship (EER) Model Chapter 8 The Enhanced Entity- Relationship (EER) Model Copyright 2011 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Chapter 8 Outline Subclasses, Superclasses, and Inheritance Specialization

More information

Module 2 : Entity-Relationship Model 15

Module 2 : Entity-Relationship Model 15 Module 2 : Entity-Relationship Model 15 Module-02 Entity Relationship Data Model 2.1 Motivation Data modeling is an essential step in the process of creating any Database Application. It helps Database

More information

Data about data is database Select correct option: True False Partially True None of the Above

Data about data is database Select correct option: True False Partially True None of the Above Within a table, each primary key value. is a minimal super key is always the first field in each table must be numeric must be unique Foreign Key is A field in a table that matches a key field in another

More information

4. Entity Relationship Model

4. Entity Relationship Model 4. Entity Relationship Model a) ER-Model: Used to construct conceptual data model, representing the structure and constraints of a database, which is not dependent on a software (like DBMS) or any data

More information

FINAL EXAM REVIEW. CS121: Introduction to Relational Database Systems Fall 2018 Lecture 27

FINAL EXAM REVIEW. CS121: Introduction to Relational Database Systems Fall 2018 Lecture 27 FINAL EXAM REVIEW CS121: Introduction to Relational Database Systems Fall 2018 Lecture 27 Final Exam Overview 2 Unlimited time, multiple sittings Open book, notes, MySQL database, etc. (the usual) Primary

More information

Conceptual Data Modeling and the Entity- Relationship Model. Department of Computer Science Northern Illinois University September 2014

Conceptual Data Modeling and the Entity- Relationship Model. Department of Computer Science Northern Illinois University September 2014 Conceptual Data Modeling and the Entity- Relationship Model Department of Computer Science Northern Illinois University September 2014 Data Models A means of describing the structure of the data A set

More information

Database Systems. Overview - important points. Lecture 5. Some introductory information ERD diagrams Normalization Other stuff 08/03/2015

Database Systems. Overview - important points. Lecture 5. Some introductory information ERD diagrams Normalization Other stuff 08/03/2015 Lecture 5 Database Systems Instructor: M.Imran Khalil Imrankhalil3@gmail.com Resource:Imrankhalil3.wordpress.com University of Sargodha Canal Campus Lahore Overview - important points Some introductory

More information

Chapter 3 Database Modeling and Design II. Database Modeling

Chapter 3 Database Modeling and Design II. Database Modeling Chapter 3 Database Modeling and Design II. Database Modeling Dr. Eng. Shady Aly 1 Data modeling تمثيل مجرد A data model is abstract representation of the data on which the IS application is to be based

More information

Lecture 14 of 42. E-R Diagrams, UML Notes: PS3 Notes, E-R Design. Thursday, 15 Feb 2007

Lecture 14 of 42. E-R Diagrams, UML Notes: PS3 Notes, E-R Design. Thursday, 15 Feb 2007 Lecture 14 of 42 E-R Diagrams, UML Notes: PS3 Notes, E-R Design Thursday, 15 February 2007 William H. Hsu Department of Computing and Information Sciences, KSU KSOL course page: http://snipurl.com/va60

More information

DATABASE MANAGEMENT SYSTEM

DATABASE MANAGEMENT SYSTEM DATABASE MANAGEMENT SYSTEM For COMPUTER SCIENCE DATABASE MANAGEMENT. SYSTEM SYLLABUS ER model. Relational model: relational algebra, tuple calculus, SQL. Integrity constraints, normal forms. File organization,

More information

1/24/2012. Chapter 7 Outline. Chapter 7 Outline (cont d.) CS 440: Database Management Systems

1/24/2012. Chapter 7 Outline. Chapter 7 Outline (cont d.) CS 440: Database Management Systems CS 440: Database Management Systems Chapter 7 Outline Using High-Level Conceptual Data Models for Database Design A Sample Database Application Entity Types, Entity Sets, Attributes, and Keys Relationship

More information

Unit 2 - Data Modeling. Pratian Technologies (India) Pvt. Ltd.

Unit 2 - Data Modeling. Pratian Technologies (India) Pvt. Ltd. Unit 2 - Data Modeling Pratian Technologies (India) Pvt. Ltd. Topics Information Engineering Approaches to IS Developments SDLC Prototyping ER Modeling Why Data Modeling? Definition Information Engineering

More information

Outline. Database Management Systems (DBMS) Database Management and Organization. IT420: Database Management and Organization

Outline. Database Management Systems (DBMS) Database Management and Organization. IT420: Database Management and Organization Outline IT420: Database Management and Organization Dr. Crăiniceanu Capt. Balazs www.cs.usna.edu/~adina/teaching/it420/spring2007 Class Survey Why Databases (DB)? A Problem DB Benefits In This Class? Admin

More information

Chapter 7: Entity-Relationship Model

Chapter 7: Entity-Relationship Model Chapter 7: Entity-Relationship Model, 7th Ed. See www.db-book.com for conditions on re-use Chapter 7: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram Design Issues Weak Entity

More information

ER modeling. Lecture 4

ER modeling. Lecture 4 ER modeling Lecture 4 1 Copyright 2007 STI - INNSBRUCK Today s lecture ER modeling Slides based on Introduction to Entity-relationship modeling at http://www.inf.unibz.it/~franconi/teaching/2000/ct481/er-modelling/

More information

Basant Group of Institution

Basant Group of Institution Basant Group of Institution Visual Basic 6.0 Objective Question Q.1 In the relational modes, cardinality is termed as: (A) Number of tuples. (B) Number of attributes. (C) Number of tables. (D) Number of

More information

Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Slide 4-1

Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Slide 4-1 Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Slide 4-1 Chapter 4 Enhanced Entity-Relationship (EER) Modeling Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Chapter Outline EER stands for

More information

Mahathma Gandhi University

Mahathma Gandhi University Mahathma Gandhi University BSc Computer science III Semester BCS 303 OBJECTIVE TYPE QUESTIONS Choose the correct or best alternative in the following: Q.1 In the relational modes, cardinality is termed

More information

ER DIAGRAM ER) diagram, a graphical representation of entities and their relationships to each other, typically used in computing in regard to the

ER DIAGRAM ER) diagram, a graphical representation of entities and their relationships to each other, typically used in computing in regard to the ER DIAGRAM ER) diagram, a graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems.

More information

SOFTWARE ENGINEERING Prof.N.L.Sarda Computer Science & Engineering IIT Bombay. Lecture #10 Process Modelling DFD, Function Decomp (Part 2)

SOFTWARE ENGINEERING Prof.N.L.Sarda Computer Science & Engineering IIT Bombay. Lecture #10 Process Modelling DFD, Function Decomp (Part 2) SOFTWARE ENGINEERING Prof.N.L.Sarda Computer Science & Engineering IIT Bombay Lecture #10 Process Modelling DFD, Function Decomp (Part 2) Let us continue with the data modeling topic. So far we have seen

More information

The Entity Relationship Model

The Entity Relationship Model The Entity Relationship Model CPS352: Database Systems Simon Miner Gordon College Last Revised: 2/4/15 Agenda Check-in Introduction to Course Database Environment (db2) SQL Group Exercises The Entity Relationship

More information

Chapter 7: Entity-Relationship Model. Chapter 7: Entity-Relationship Model

Chapter 7: Entity-Relationship Model. Chapter 7: Entity-Relationship Model Chapter 7: Entity-Relationship Model Database System Concepts, 6 th Ed. See www.db-book.com for conditions on re-use Chapter 7: Entity-Relationship Model Design Process Modeling Constraints E-R Diagram

More information

A l Ain University Of Science and Technology

A l Ain University Of Science and Technology A l Ain University Of Science and Technology 4 Handout(4) Database Management Principles and Applications The Entity Relationship (ER) Model http://alainauh.webs.com/ http://www.comp.nus.edu.sg/~lingt

More information

The Entity-Relationship Model. Steps in Database Design

The Entity-Relationship Model. Steps in Database Design The Entity-Relationship Model Steps in Database Design 1) Requirement Analysis Identify the data that needs to be stored data requirements Identify the operations that need to be executed on the data functional

More information

MIS Database Systems Entity-Relationship Model.

MIS Database Systems Entity-Relationship Model. MIS 335 - Database Systems Entity-Relationship Model http://www.mis.boun.edu.tr/durahim/ Ahmet Onur Durahim Learning Objectives Database Design Main concepts in the ER model? ER Diagrams Database Design

More information

CS/INFO 330 Entity-Relationship Modeling. Announcements. Goals of This Lecture. Mirek Riedewald

CS/INFO 330 Entity-Relationship Modeling. Announcements. Goals of This Lecture. Mirek Riedewald CS/INFO 330 Entity-Relationship Modeling Mirek Riedewald mirek@cs.cornell.edu Announcements Office hour update (see class homepage) First homework assignment will be available from CMS later today Some

More information

Chapter 17. Methodology Logical Database Design for the Relational Model

Chapter 17. Methodology Logical Database Design for the Relational Model Chapter 17 Methodology Logical Database Design for the Relational Model Chapter 17 - Objectives How to derive a set of relations from a conceptual data model. How to validate these relations using the

More information

CS403- Database Management Systems Solved MCQS From Midterm Papers. CS403- Database Management Systems MIDTERM EXAMINATION - Spring 2010

CS403- Database Management Systems Solved MCQS From Midterm Papers. CS403- Database Management Systems MIDTERM EXAMINATION - Spring 2010 CS403- Database Management Systems Solved MCQS From Midterm Papers April 29,2012 MC100401285 Moaaz.pk@gmail.com Mc100401285@gmail.com PSMD01 CS403- Database Management Systems MIDTERM EXAMINATION - Spring

More information

1. Data Model, Categories, Schemas and Instances. Outline

1. Data Model, Categories, Schemas and Instances. Outline Chapter 2: Database System Concepts and Architecture Outline Ramez Elmasri, Shamkant B. Navathe(2016) Fundamentals of Database Systems (7th Edition),pearson, isbn 10: 0-13-397077-9;isbn-13:978-0-13-397077-7.

More information

Database Management System CS403 Lecture No 1 Database definitions: 1 A shared collection of logically related data, designed to meet the information

Database Management System CS403 Lecture No 1 Database definitions: 1 A shared collection of logically related data, designed to meet the information Database Management System CS403 Lecture No 1 Database definitions: 1 A shared collection of logically related data, designed to meet the information needs of multiple users in an organization. 2 A Computerized

More information

Database Management Systems LECTURE NOTES 2

Database Management Systems LECTURE NOTES 2 Database Management Systems LECTURE NOTES 2 Relation: A table; Tuple: A row in a table; Attribute: A column in a table Degree: number of attributes; Cardinality: number of tuples Entity and Entity Sets:

More information

System Analysis And Design Methods ENTITY RELATIONSHIP DIAGRAM (ERD) Prof. Ali Khaleghi Eng. Hadi Haedar

System Analysis And Design Methods ENTITY RELATIONSHIP DIAGRAM (ERD) Prof. Ali Khaleghi Eng. Hadi Haedar 1 System Analysis And Design Methods ENTITY RELATIONSHIP DIAGRAM (ERD) Prof. Ali Khaleghi Eng. Hadi Haedar Overview DATABASE ARCHITECTURE 2 External level concerned with the way individual users see the

More information

The En'ty Rela'onship Model

The En'ty Rela'onship Model The En'ty Rela'onship Model Debapriyo Majumdar DBMS Fall 2016 Indian Statistical Institute Kolkata Slides re-used, with minor modification, from Silberschatz, Korth and Sudarshan www.db-book.com Outline

More information

THE ENHANCED ER (EER) MODEL CHAPTER 8 (6/E) CHAPTER 4 (5/E)

THE ENHANCED ER (EER) MODEL CHAPTER 8 (6/E) CHAPTER 4 (5/E) THE ENHANCED ER (EER) MODEL CHAPTER 8 (6/E) CHAPTER 4 (5/E) 2 CHAPTER 8 OUTLINE Extending the ER model Created to design more accurate database schemas Reflect the data properties and constraints more

More information

The Relational Model

The Relational Model The Relational Model What is the Relational Model Relations Domain Constraints SQL Integrity Constraints Translating an ER diagram to the Relational Model and SQL Views A relational database consists

More information

B.H.GARDI COLLEGE OF MASTER OF COMPUTER APPLICATION. Ch. 1 :- Introduction Database Management System - 1

B.H.GARDI COLLEGE OF MASTER OF COMPUTER APPLICATION. Ch. 1 :- Introduction Database Management System - 1 Basic Concepts :- 1. What is Data? Data is a collection of facts from which conclusion may be drawn. In computer science, data is anything in a form suitable for use with a computer. Data is often distinguished

More information

CMSC 424 Database design Lecture 2: Design, Modeling, Entity-Relationship. Book: Chap. 1 and 6. Mihai Pop

CMSC 424 Database design Lecture 2: Design, Modeling, Entity-Relationship. Book: Chap. 1 and 6. Mihai Pop CMSC 424 Database design Lecture 2: Design, Modeling, Entity-Relationship Book: Chap. 1 and 6 Mihai Pop Administrative issues TA: Sharath Srinivas TA office hours: Mon 10-11:30, Wed 3-4:30, AVW 1112 Glue

More information

DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL. CS121: Relational Databases Fall 2017 Lecture 14

DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL. CS121: Relational Databases Fall 2017 Lecture 14 DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL CS121: Relational Databases Fall 2017 Lecture 14 Designing Database Applications 2 Database applications are large and complex A few of the many design

More information

Chapter 2 Conceptual Modeling. Objectives

Chapter 2 Conceptual Modeling. Objectives Chapter 2 Conceptual Modeling Basic Entity Relationship Diagrams 1 Objectives Definition of terms Importance of data modeling Write good names and definitions for entities, relationships, and attributes

More information

Conceptual Database Design

Conceptual Database Design Conceptual Database Design Fall 2009 Yunmook Nah Department of Electronics and Computer Engineering Dankook University Conceptual Database Design Methodology Chapter 15, Connolly & Begg Steps to Build

More information

COMP102: Introduction to Databases, 13

COMP102: Introduction to Databases, 13 COMP102: Introduction to Databases, 13 Dr Muhammad Sulaiman Khan Department of Computer Science University of Liverpool U.K. 7 March, 2011 Logical Database Design: Enhanced ER Modeling Specific topics

More information

VARDHAMAN COLLEGE OF ENGINEERING Shamshabad , Hyderabad B.Tech. CSE IV Semester (VCE - R11) T P C 3+1* -- 4 (A1511) DATABASE MANAGEMENT SYSTEMS

VARDHAMAN COLLEGE OF ENGINEERING Shamshabad , Hyderabad B.Tech. CSE IV Semester (VCE - R11) T P C 3+1* -- 4 (A1511) DATABASE MANAGEMENT SYSTEMS 1 VARDHAMAN COLLEGE OF ENGINEERING Shamshabad 501 218, Hyderabad B.Tech. CSE IV Semester (VCE - R11) T P C 3+1* -- 4 (A1511) DATABASE MANAGEMENT SYSTEMS UNIT - I INTRODUCTION: History of database systems,

More information

CS 338 The Enhanced Entity-Relationship (EER) Model

CS 338 The Enhanced Entity-Relationship (EER) Model CS 338 The Enhanced Entity-Relationship (EER) Model Bojana Bislimovska Spring 2017 Major research Outline EER model overview Subclasses, superclasses and inheritance Specialization and generalization Modeling

More information

Non-overlappingoverlapping. Final outcome of the worked example On pages R&C pages R&C page 157 Fig 3.52

Non-overlappingoverlapping. Final outcome of the worked example On pages R&C pages R&C page 157 Fig 3.52 Objectives Computer Science 202 Database Systems: Entity Relation Modelling To learn what a conceptual model is and what its purpose is. To learn the difference between internal models and external models.

More information

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 7 Data Modeling with Entity Relationship Diagrams

Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition. Chapter 7 Data Modeling with Entity Relationship Diagrams Database Principles: Fundamentals of Design, Implementation, and Management Tenth Edition Chapter 7 Data Modeling with Entity Relationship Diagrams Objectives In this chapter, students will learn: The

More information

Unit I. By Prof.Sushila Aghav MIT

Unit I. By Prof.Sushila Aghav MIT Unit I By Prof.Sushila Aghav MIT Introduction The Need for Databases Data Models Relational Databases Database Design Storage Manager Query Processing Transaction Manager DBMS Applications DBMS contains

More information

Data Modeling using ER Model

Data Modeling using ER Model Data Modeling using ER Model Database design process - requirements collection and analysis: database requirements and functional requirements - conceptual DB design using a high-level model: easier to

More information

CSCC43H: Introduction to Databases

CSCC43H: Introduction to Databases CSCC43H: Introduction to Databases Lecture 2 Wael Aboulsaadat Acknowledgment: these slides are partially based on Prof. Garcia-Molina & Prof. Ullman slides accompanying the course s textbook. CSCC43: Introduction

More information

II B.Sc(IT) [ BATCH] IV SEMESTER CORE: RELATIONAL DATABASE MANAGEMENT SYSTEM - 412A Multiple Choice Questions.

II B.Sc(IT) [ BATCH] IV SEMESTER CORE: RELATIONAL DATABASE MANAGEMENT SYSTEM - 412A Multiple Choice Questions. Dr.G.R.Damodaran College of Science (Autonomous, affiliated to the Bharathiar University, recognized by the UGC)Re-accredited at the 'A' Grade Level by the NAAC and ISO 9001:2008 Certified CRISL rated

More information

Entity-Relationship Model &

Entity-Relationship Model & Entity-Relationship Model & IST 210 Diagram Todd S. Bacastow IST 210: Organization of data 2/1/2004 1 Design Principles Setting client has (possibly vague) idea of what he/she wants. YOUR task must design

More information

LAB 2 Notes. Conceptual Design ER. Logical DB Design (relational) Schema Refinement. Physical DD

LAB 2 Notes. Conceptual Design ER. Logical DB Design (relational) Schema Refinement. Physical DD LAB 2 Notes For students that were not present in the first lab TA Web page updated : http://www.cs.ucr.edu/~cs166/ Mailing list Signup: http://www.cs.ucr.edu/mailman/listinfo/cs166 The general idea of

More information

Database Systems: Design, Implementation, and Management Tenth Edition. Chapter 4 Entity Relationship (ER) Modeling

Database Systems: Design, Implementation, and Management Tenth Edition. Chapter 4 Entity Relationship (ER) Modeling Database Systems: Design, Implementation, and Management Tenth Edition Chapter 4 Entity Relationship (ER) Modeling Objectives In this chapter, students will learn: The main characteristics of entity relationship

More information