MIS Database Systems Entity-Relationship Model.

Size: px
Start display at page:

Download "MIS Database Systems Entity-Relationship Model."

Transcription

1 MIS Database Systems Entity-Relationship Model Ahmet Onur Durahim

2 Learning Objectives Database Design Main concepts in the ER model? ER Diagrams

3 Database Design and ER Diagrams Requirements Analysis: find out what the users want from the database What data is to be stored in the DB What applications must be built on top of it What operations are most frequent and subject to performance requirements Conceptual Database Design: create a simple description of the data that closely matches how users and developers think of the data A high-level (semantic) description of data to be stored in the DB along with the constraints known to hold over this data Carried out using the ER Model Logical Database Design: choose DBMS to implement conceptual database design Convert conceptual DB design (ER schema) into a DB schema in the data model of the chosen DBMS (relational DB schema)

4 DB Design Schema Refinement Analyze the collection of relations in relational DB schema to identify potential problems and refine it (- Normalization of the relations) Physical DB Design Consider expected workloads to refine for meeting the desired performance criteria Building indexes on tables Clustering some tables Redesign of parts of the DB schema Application and Security Design Identify entities (users, departments) and relevant roles of each entity Enforce access rules: For each role, identify the parts of the DB that must be accessible and must not be accessible

5 Entity-Relationship Model Before developing your database application, you need to Collect the requirements Build a conceptual database design ER Model: used to describe the data involved in an enterprise in terms of objects and relationships Widely accepted standard for initial (conceptual) database design

6 Entity-Relationship Model Conceptual DB design: What information about these entities and relationships should we store in the database? What are the integrity constraints or business rules that hold? A database schema in the ER Model can be represented pictorially ER diagrams Can map an ER diagram into a relational schema

7 Entity-Relationship Diagram ssn lot cost p age Employees Policy Dependents

8 Key Concepts of ER Model Entities and Relationships Entities An object that is capable of independent existence and can be uniquely identified can be distinguished from other objects Employee Student Item An entity is described using a set of attributes ssn sid type

9 Entity set Key Concepts of ER Model A collection of similar entities share the same set of properties/attributes except in ISA hierarchies Reflects the level of detail at to represent information about entities Students Onur Alp Zubeyde Esra Arzu Ahmet

10 Key Concepts of ER Model Entity set may overlap Any example? Students Onur Zubeyde Arzu Alp Esra Ahmet Employees Mert Emrecan Mehmet

11 Key Concepts of ER Model Each entity sets has attributes Each attribute has a domain Domain: set of permitted values attribute (set of 20-character string) age attribute (set of integers between 0-150) Each entity set has a key minimal set of attributes whose values uniquely identify an entity in the set denoted by underlining the attribute in the ERdiagram Employee ssn address

12 Key Concepts of ER Model Relationships Association (relation) among two or more entities Ahmet is enrolled in MIS335 Enrolled Works_In Relationship sets A collection of similar relationships Share the same properties

13 Key Concepts of ER Model Relationships also has attributes Descriptive attributes: used to record the information about the relationship Ahmet Works_In University since 2014 Employee Works_In ssn address since

14 ER Model c sid Student Enrolled Course cid semester Rectangles : Entity sets Diamonds : Relationship Sets Ellipses/Oval : Attributes

15 ER Model Degree of a relationship set is the number of entity sets that participate in a relationship Binary relationship sets involve two entity sets sid Student Enrolled semester Course cid c

16 ER Model Ternary relationship sets involve three entity sets address Locations capacity Employee Works_In Departments ssn since did d budget

17 An Instance of the WorksIn Relationship Set

18 ER Model The set of entities that participate in a relationship set may belong to the same entity set Each entity plays a different role in such a relationship Employees ssn Employees supervisor subordinate Reports_To Reports_To => Unary relationship

19 ER Model The set of entities that participate in a relationship set may belong to the same entity set Each entity plays a different role in such a relationship Students sid Student tutor tutee Helps

20 Cardinality Mappings One-to-One (1-1) One occurrence of an entity relates to only one occurrence in another entity rarely exists in practice consider combining them into one entity Example: an employee is allocated a company car, which can only be driven by that employee One-to-Many (1-M) / Many-to-One (M-1) One occurrence in an entity relates to many occurrences in another entity Example: an employee works in one department but a department has many employees.

21 Cardinality Mappings Many-to-Many (M-N) Many occurrences in an entity relate to many occurrences in another entity The normalisation process would prevent any such relationships Rarely exist They occur because an entity has been missed. Example: an employee may work on several projects at the same time and a project has a team of many employees. In the normalisation process this many-to-many is resolved by the entity Project Team.

22 Cardinality Mappings 1-to-1 1-to-Many Many-to-1 Many-to-Many

23 ER Model Key Constraints Employees Works_In Departments ssn since did d since An employee can Work In multiple departments and a department can have multiple employees. What is the type of this relationship? Many-to-Many

24 ER Model Key Constraints Employees Manages Departments ssn since did d An employee can Manage multiple departments, but a department can be managed by only one employee (Manager) What is the type of this relationship? since This is called a key constraint (the restriction that each department has at most one manager) denoted by an arrow 1-to-Many

25 An Instance of the Manages Relationship Set Department with did = 60 violates the key constraint of the Manages relationship Instance of Manages relationship that satisfies the key constraint of the Manages relationship

26 Participation Constraints If every department is required to have a manager, this requirement is a participation constraint The participation of the entity set Departments in the relationship set Manages is total The participation of the entity set Employees in the relationship set Manages is partial Since not every employee gets to manage a department Total participation constraint of an Entity set in a relationship set is indicated by connecting them by thick line Employees Manages Departments ssn since did d since

27 Participation Constraints If each employee works in at least one department, and if each department has at least one employee Total or Partial Participation of Employees & Departments entities Works_In since Employees Manages Departments ssn since did d since

28 Weak Entities Weak Entity: Entity set that does not include a key A weak entity can be identified uniquely only by considering the primary key of another entity (called identifying owner) Set of attributes of a weak entity set that uniquely identify a weak entity for a given owner entity => partial key A weak entity set is denoted by a rectangle with thick lines Employees Policy Dependents ssn cost age p

29 Weak Entities A weak entity can be identified uniquely only by considering the primary key of another entity (called identifying owner) A weak entity set is denoted by a rectangle with thick lines The relationship between a weak entity and the owner entity is denoted by a diamond with thick lines Employees Policy Dependents ssn cost age p

30 Weak Entities A weak entity can be identified uniquely only by considering the primary key of another entity (called identifying owner) What can you say about the constraints on the identifying relationship? (i.e., participation and key constraints) Employees Policy Dependents ssn cost age p

31 Weak Entities What can you say about the constraints on the identifying relationship? (i.e., participation and key constraints) Owner entity set and weak entity set must participate in a one-to-many relationship set (one owner, many weak entities) Weak entity set must have total participation in this identifying relationship set Employees Policy Dependents ssn cost age p

32 Class/ISA ( is a ) Hierarchies Classify entities into subclasses Every entity in a subclass also belongs to superclass (Employees) The attributes for the entity set Employees are inherited by the entity set Hourly_Emps Hourly_Emps ISA Employees Reasons for using ISA: To add descriptive attributes specific to a subclass i.e. not appropriate for all entities in the superclass hourly_wages To identify entities that participate in a relationship i.e. not all superclass entities participate Hourly_Emps hours_worked ssn Employees ISA Contract_Emps contractid

33 Class/ISA ( is a ) Hierarchies Specialization: process of identifying subsets of an entity set (Employees) that share some distinguishing characteristic Employees is specialized into subclasses Generalization: process of identifying some common characteristics of a collection of entity sets and creating a new entity set that contains entities possessing these common characteristics Hourly_Emps and Contract_Emps are generalized by Employees Hourly_Emps ssn Employees ISA Contract_Emps hourly_wages hours_worked contractid

34 Class/ISA ( is a ) Hierarchies Overlap Constraints: determine whether two subclasses are allowed to contain the same entity Can Ahmet belong to both Contract_Emps entity and Hourly_Emps? Covering Constraints: determine whether the entities in the subclasses collectively include all entities in the superclass Does every Employees entity have to belong to one of Hourly_Emps and Contract_Emps? ssn Employees ISA Hourly_Emps Contract_Emps hourly_wages hours_worked contractid

35 Aggregation ssn Used to indicate that a relationship set (denoted by a dashed box) participates in another relationship set Allows us to treat a relationship set as an entity set for purposes of participation in other relationships A department that sponsors a project might assign employees to Monitor the Sponsorship Monitors should be a relationship that associates a Sponsors relationship with an Employees entity started_on Projects pbudget Aggregation vs. Ternary relationship: Monitors is a distinct relationship, with a descriptive attribute Also, can say that each sponsorship is monitored by at most one employee pid Employees Monitors until Sponsors Departments did d since budget

36 Conceptual Design Using the ER Model Design choices: Should a concept be modeled as an entity or an attribute? Should a concept be modeled as an entity or a relationship? Identifying relationships: Binary or ternary? Aggregation? Constraints in the ER Model: A lot of data semantics can (and should) be captured But some constraints cannot be captured in ER diagrams

37 Entity vs. Attribute Should address be an attribute of Employees or an entity (connected to Employees by a relationship)? Depends upon the use we want to make of address information, and the semantics of the data: If only one address is to be recorded per employee Use attribute address If we have several addresses per employee address must be an entity (since attributes cannot be set-valued) If we want to capture the structure (break down address into country, city, street, etc.) of an address e.g., we want to retrieve employees in a given city address must be modeled as an entity (since attribute values are atomic)

38 Entity vs. Attribute Works_In does not allow an employee to work in a department for two or more periods This possibility is ruled out by the ER diagram s semantic, because relationship is uniquely identified by the participating entities (without reference to its descriptive attributes) Similar to the problem of wanting to record several addresses for an employee We want to record several values of the descriptive attributes for each instance of this relationship Accomplished by introducing new entity set, Duration Employees ssn from Employees ssn from to Works_In Duration Works_In Departments did d budget to Departments did d budget

39 Entity vs. Relationship ER diagram is OK if a manager gets a separate discretionary budget for each department What if a manager gets a discretionary budget that covers all managed departments? Redundancy: dbudget stored for each dept managed by manager Misleading: Suggests dbudget associated with departmentmgr combination Employees Employees ISA since dbudget Manages Departments ssn did d budget ssn Manages Departments did d since Managers dbudget budget

40 Entity vs. Relationship ER diagram is OK if a manager gets a separate discretionary budget for each department What if a manager gets a discretionary budget that covers all managed departments? Redundancy: dbudget stored for each dept managed by manager Misleading: Suggests dbudget associated with departmentmgr combination Redundancies are eliminated by Normalization technique Employees Employees ISA Managers since dbudget Manages Departments ssn did d budget ssn since Manages Departments did d dbudget budget

41 Binary vs. Ternary Relationship ssn p age Models the situation where; An employee can own several policies Each policy can be owned by several employees Each dependent can be covered by several policies Employees policyid Covers Policies cost Dependents

42 Binary vs. Ternary Relationship If we have additional requirements; A policy cannot be owned jointly by two or more employees Every policy must be owned by some employee Dependents is a weak entity, and uniquely identified by taking p in conjunction with policyid of a policy entity ER diagram is inaccurate What are the additional constraints in the 2nd diagram? Employees Employees Bad design ssn ssn Covers Policies policyid cost p age Dependents p age Dependents Better design Purchaser Beneficiary Policies policyid cost

43 Binary vs. Ternary Relationship (Contd.) An example in the other direction: A ternary relation Contracts relates entity sets Parts, Departments and Suppliers, and has descriptive attribute qty. No combination of binary relationships is an adequate substitute: S can-supply P, D needs P, and D deals-with S does not imply that D has agreed to buy P from S How do we record qty?

44 Summary of Conceptual Design Conceptual design follows requirements analysis Yields a high-level description of data to be stored ER model popular for conceptual design Constructs are expressive, close to the way people think about their applications Basic constructs entities, relationships, and attributes (of entities and relationships) Some additional constructs weak entities, ISA hierarchies, and aggregation Note: There are many variations on ER model

45 Summary of Conceptual Design Several kinds of integrity constraints can be expressed in the ER model: key constraints participation constraints overlap/covering constraints for ISA hierarchies Some foreign key constraints are also implicit in the definition of a relationship set Some constraints (notably, functional dependencies) cannot be expressed in the ER model Constraints play an important role in determining the best database design for an enterprise

46 Summary of Conceptual Design ER design is subjective There are often many ways (alternatives) to model a given scenario Common choices include: Entity vs. attribute, Entity vs. relationship Binary or n-ary relationship Whether or not to use ISA hierarchies / aggregation To ensuring good database design: Resulting relational schema should be analyzed and refined further FD information and normalization techniques are especially useful

47 ER Modeling Question - 0 Should explain the following terms: entity, relationship, entity set, relationship set, attribute, domain, one-to-many relationship, many-to-many relationship, participation constraint, overlap constraint, covering constraint, weak entity set, aggregation, role indicator.

48 Attribute - a property or description of an entity. A toy department employee entity could have attributes describing the employee s, salary, and years of service. Domain - a set of possible values for an attribute. Entity - an object in the real world that is distinguishable from other objects such as the green dragon toy. Entity set - a collection of similar entities such as all of the toys in the toy department. Relationship - an association among two or more entities. Relationship set - a collection of similar relationships One-to-many relationship - a key constraint that indicates that one entity can be associated with many of another entity. An example of a one-to-many relationship is when an employee can work for only one department, and a department can have many employees. Many-to-many relationship - a key constraint that indicates that many of one entity can be associated with many of another entity. An example of a many-to-many relationship is employees and their hobbies: a person can have many different hobbies, and many people can have the same hobby.

49 Participation constraint - a participation constraint determines whether relationships must involve certain entities An example is if every department entity has a manager entity Participation constraints can either be total or partial A total participation constraint says that every department has a manager A partial participation constraint says that every employee does not have to be a manager Overlap constraint - within an ISA hierarchy, an overlap constraint determines whether or not two subclasses can contain the same entity Covering constraint - within an ISA hierarchy, a covering constraint determines where the entities in the subclasses collectively include all entities in the superclass For example, with an Employees entity set with subclasses HourlyEmployee and SalaryEmployee, does every Employee entity necessarily have to be within either HourlyEmployee or SalaryEmployee? Weak entity set - an entity that cannot be identified uniquely without considering some primary key attributes of another identifying owner entity An example is including Dependent information for employees for insurance purposes Aggregation - a feature of the entity relationship model that allows a relationship set to participate in another relationship set. This is indicated on an ER diagram by drawing a dashed box around the aggregation Role indicator - If an entity set plays more than one role, role indicators describe the different purpose in the relationship An example is a single Employee entity set with a relation Reports-To that relates supervisors and subordinates

50 ER Modeling Example - 1 A university database contains information about professors (identified by social security number, or SSN) and courses (identified by courseid) Professors teach courses; each of the following situations concerns the Teaches relationship set. For each situation, draw an ER diagram that describes it (assuming no further constraints hold)

51 ER Modeling Example - 1 Professors can teach the same course in several semesters, and each offering must be recorded Professors can teach the same course in several semesters, and only the most recent such offering needs to be recorded. (Assume this condition applies in all subsequent questions.) Every professor must teach some course

52 ER Modeling Example - 1 Every professor teaches exactly one course (no more, no less) Every professor teaches exactly one course (no more, no less), and every course must be taught by some professor Now suppose that certain courses can be taught by a team of professors jointly, but it is possible that no one professor in a team can teach the course. Model this situation, introducing additional entity sets and relationship sets if necessary

53 Different ER Modeling Notations

54 Chen vs. Crow s Foot Notation

55 Crow s Foot Notation

The Entity-Relationship Model

The Entity-Relationship Model The Entity-Relationship Model Chapter 2 Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.) What are the entities

More information

The Entity-Relationship Model

The Entity-Relationship Model The Entity-Relationship Model Chapter 2 Database Management Systems, R. Ramakrishnan and J. Gehrke 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.) What are the entities

More information

The Entity-Relationship Model. Overview of Database Design. ER Model Basics. (Ramakrishnan&Gehrke, Chapter 2)

The Entity-Relationship Model. Overview of Database Design. ER Model Basics. (Ramakrishnan&Gehrke, Chapter 2) The Entity-Relationship Model (Ramakrishnan&Gehrke, Chapter 2) CS 432 Fall 2007 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.) What are the entities and relationships

More information

The Entity-Relationship (ER) Model

The Entity-Relationship (ER) Model The Entity-Relationship (ER) Model (Study Cow book Chapter 2) Comp 521 Files and Databases Fall 2012 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.) What are the entities

More information

Introduction to Database Design. Dr. Kanda Runapongsa Dept of Computer Engineering Khon Kaen University

Introduction to Database Design. Dr. Kanda Runapongsa Dept of Computer Engineering Khon Kaen University Introduction to Database Design Dr. Kanda Runapongsa (krunapon@kku.ac.th) Dept of Computer Engineering Khon Kaen University Overview What are the steps in designing a database? Why is the ER model used

More information

Database Management Systems. Chapter 2 Part 2

Database Management Systems. Chapter 2 Part 2 Database Management Systems Chapter 2 Part 2 Introduction to Database Design Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Class Hierarchies Classify entities sets into Super-class and

More information

Introduction to Database Design

Introduction to Database Design ICS 321 Fall 2009 Introduction to Database Design Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa 09/03/2009 Lipyeow Lim -- University of Hawaii at Manoa

More information

The Entity-Relationship Model. Overview of Database Design

The Entity-Relationship Model. Overview of Database Design The Entity-Relationship Model Chapter 2, Chapter 3 (3.5 only) Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.)

More information

Database Applications (15-415)

Database Applications (15-415) Database Applications (15-415) The Entity Relationship Model Lecture 2, January 15, 2014 Mohammad Hammoud Today Last Session: Course overview and a brief introduction on databases and database systems

More information

CIS 330: Web-driven Web Applications. Lecture 2: Introduction to ER Modeling

CIS 330: Web-driven Web Applications. Lecture 2: Introduction to ER Modeling CIS 330: Web-driven Web Applications Lecture 2: Introduction to ER Modeling 1 Goals of This Lecture Understand ER modeling 2 Last Lecture Why Store Data in a DBMS? Transactions (concurrent data access,

More information

Contents. Database. Information Policy. C03. Entity Relationship Model WKU-IP-C03 Database / Entity Relationship Model

Contents. Database. Information Policy. C03. Entity Relationship Model WKU-IP-C03 Database / Entity Relationship Model Information Policy Database C03. Entity Relationship Model Code: 164323-03 Course: Information Policy Period: Spring 2013 Professor: Sync Sangwon Lee, Ph. D 1 Contents 01. Overview of Database Design 02.

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

The Entity-Relationship (ER) Model 2

The Entity-Relationship (ER) Model 2 The Entity-Relationship (ER) Model 2 Week 2 Professor Jessica Lin Keys Differences between entities must be expressed in terms of attributes. A superkey is a set of one or more attributes which, taken

More information

Introduction to Data Management. Lecture #3 (Conceptual DB Design) Instructor: Chen Li

Introduction to Data Management. Lecture #3 (Conceptual DB Design) Instructor: Chen Li Introduction to Data Management Lecture #3 (Conceptual DB Design) Instructor: Chen Li 1 Announcements v HW #1 is now available v Today s plan Conceptual DB design, cont. Advanced ER concepts 2 Weak Entities

More information

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd.

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd. The Entity- Relationship Model CS 186 Fall 2002: Lecture 2 R &G - Chapter 2 A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. And I think what we got on

More information

Introduction to Database Design

Introduction to Database Design Introduction to Database Design UVic C SC 370 Daniel M German Introduction to Database Design (1.2.0) CSC 370 4/5/2005 14:52 p.1/33 Overview What are the steps in designing a database? What is the entity-relationship

More information

Modeling Your Data. Chapter 2. cs542 1

Modeling Your Data. Chapter 2. cs542 1 Modeling Your Data Chapter 2 cs542 1 Part II Discussion of the Model: Good Design/ Bad Design cs542 2 Design : The Obvious Use meaningful and descriptive s (it s for the human after all) Keep as simple

More information

Introduction to Data Management. Lecture #3 (Conceptual DB Design)

Introduction to Data Management. Lecture #3 (Conceptual DB Design) Introduction to Data Management Lecture #3 (Conceptual DB Design) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Announcements Today s plan:

More information

OVERVIEW OF DATABASE DEVELOPMENT

OVERVIEW OF DATABASE DEVELOPMENT DATABASE SYSTEMS I WEEK 2: THE ENTITY-RELATIONSHIP MODEL OVERVIEW OF DATABASE DEVELOPMENT Requirements Analysis / Ideas High-Level Database Design Conceptual Database Design / Relational Database Schema

More information

Introduction to Database Design

Introduction to Database Design Introduction to Database Design UVic C SC 370, Fall 2002 Daniel M. German Department of Computer Science University of Victoria 2 1 Introduction to Database Design CSC 370 dmgerman@uvic.ca Overview What

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

Introduction to Data Management. Lecture #3 (Conceptual DB Design)

Introduction to Data Management. Lecture #3 (Conceptual DB Design) Introduction to Data Management Lecture #3 (Conceptual DB Design) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Announcements Reminders: Sign

More information

Database Design. ER Model. Overview. Introduction to Database Design. UVic C SC 370. Database design can be divided in six major steps:

Database Design. ER Model. Overview. Introduction to Database Design. UVic C SC 370. Database design can be divided in six major steps: Database Design Database design can be divided in six major steps: Requirements analysis Conceptual Database design (mostly done using the ER model) Logical Database design Schema refinement Physical Database

More information

Overview. Introduction to Database Design. ER Model. Database Design

Overview. Introduction to Database Design. ER Model. Database Design Introduction to Database Design UVic C SC 370 Dr. Daniel M. German Department of Computer Science Overview What are the steps in designing a database? What is the entity-relationship (ER) model? How does

More information

Overview of db design Requirement analysis Data to be stored Applications to be built Operations (most frequent) subject to performance requirement

Overview of db design Requirement analysis Data to be stored Applications to be built Operations (most frequent) subject to performance requirement ITCS 3160 Data Base Design and Implementation Jing Yang 2010 Fall Class 12: Data Modeling Using the Entity-Relationship (ER) Model Overview of db design Requirement analysis Data to be stored Applications

More information

SYLLABUS ADMIN DATABASE SYSTEMS I WEEK 2 THE ENTITY-RELATIONSHIP MODEL. Assignment #2 changed. A2Q1 moved to A3Q1

SYLLABUS ADMIN DATABASE SYSTEMS I WEEK 2 THE ENTITY-RELATIONSHIP MODEL. Assignment #2 changed. A2Q1 moved to A3Q1 DATABASE SYSTEMS I WEEK 2 THE ENTITY-RELATIONSHIP MODEL Class Time and Location: Tue 14:30-16:20 AQ3005 Thu 14:30-15:20 AQ3003 Course Website: http://www.cs.sfu.ca/cc/354/rfrank/ Instructor: Richard Frank,

More information

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd.

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd. The Entity- Relationship Model R &G - Chapter 2 A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. And I think what we got on our hands is a dead shark. Woody

More information

CSE 530A. ER Model. Washington University Fall 2013

CSE 530A. ER Model. Washington University Fall 2013 CSE 530A ER Model Washington University Fall 2013 Database Design Requirements Analysis Conceptual Database Design Creates an abstract model Logical Database Design Converts abstract model to concrete

More information

Database Design CENG 351

Database Design CENG 351 Database Design Database Design Process Requirements analysis What data, what applica;ons, what most frequent opera;ons, Conceptual database design High level descrip;on of the data and the constraint

More information

The Entity-Relationship Model

The Entity-Relationship Model The Entity-Relationship Model Chapter 2 Instructor: Vladimir Zadorozhny vladimir@sis.pitt.edu Information Science Program School of Information Sciences, University of Pittsburgh 1 Database: a Set of Relations

More information

Database Management Systems. Chapter 3 Part 2

Database Management Systems. Chapter 3 Part 2 Database Management Systems Chapter 3 Part 2 The Relational Model Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Logical DB Design: ER to Relational Entity sets to tables: CREATE TABLE

More information

ER Model Overview. The Entity-Relationship Model. Database Design Process. ER Model Basics

ER Model Overview. The Entity-Relationship Model. Database Design Process. ER Model Basics ER Model Overview The Entity-Relationship Model Davood Rafiei Developed by Peter Chen in the mid 70 s Used for the design of conceptual schema. The world is described in terms of entities relationships

More information

Entity-Relationship Diagrams

Entity-Relationship Diagrams Entity-Relationship Diagrams Fall 2017, Lecture 3 There is nothing worse than a sharp image of a fuzzy concept. Ansel Adams 1 Recall: Relational Database Management Relational DataBase Management Systems

More information

CIS 330: Applied Database Systems

CIS 330: Applied Database Systems 1 CIS 330: Applied Database Systems Lecture 3: Introduction to ER Modeling The Relational Model Johannes Gehrke johannes@cs.cornell.edu http://www.cs.cornell.edu/johannes Announcements How many laptops

More information

Database Systems. Lecture2:E-R model. Juan Huo( 霍娟 )

Database Systems. Lecture2:E-R model. Juan Huo( 霍娟 ) Database Systems Lecture2:E-R model Juan Huo( 霍娟 ) Reference slides: http://www.cs.wisc.edu/ dbbook Berkeley, Professor Eben Haber,Professor Mary Roth Review: Benefits of a DBMS 1. Data independence applications

More information

Database Applications (15-415)

Database Applications (15-415) Database Applications (15-415) The Relational Model Lecture 3, January 18, 2015 Mohammad Hammoud Today Last Session: The entity relationship (ER) model Today s Session: ER model (Cont d): conceptual design

More information

High Level Database Models

High Level Database Models ICS 321 Fall 2011 High Level Database Models Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa 9/21/2011 Lipyeow Lim -- University of Hawaii at Manoa 1 Database

More information

ENTITY-RELATIONSHIP. The database design process can be divided into six steps. The ER model is most relevant to the first three steps:

ENTITY-RELATIONSHIP. The database design process can be divided into six steps. The ER model is most relevant to the first three steps: 2 ENTITY-RELATIONSHIP MODEL The great successful men of the world have used their imaginations. They think ahead and create their mental picture, and then go to work materializing that picture in all its

More information

ER Model. CSC 343 Winter 2018 MICHAEL LIUT

ER Model. CSC 343 Winter 2018 MICHAEL LIUT ER Model CSC 343 Winter 2018 MICHAEL LIUT (MICHAEL.LIUT@UTORONTO.CA) DEPARTMENT OF MATHEMATICAL AND COMPUTATIONAL SCIENCES UNIVERSITY OF TORONTO MISSISSAUGA Overview of Database Design Conceptual Designs

More information

Data Modeling. Yanlei Diao UMass Amherst. Slides Courtesy of R. Ramakrishnan and J. Gehrke

Data Modeling. Yanlei Diao UMass Amherst. Slides Courtesy of R. Ramakrishnan and J. Gehrke Data Modeling Yanlei Diao UMass Amherst Slides Courtesy of R. Ramakrishnan and J. Gehrke 1 Outline v Conceptual Design: ER Model v Relational Model v Logical Design: from ER to Relational 2 Conceptual

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

Introduction to Data Management. Lecture #3 (E-R Design, Cont d.)

Introduction to Data Management. Lecture #3 (E-R Design, Cont d.) Introduction to Data Management Lecture #3 (E-R Design, Cont d.) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Announcements Reminders: Sign

More information

Relational Model. Topics. Relational Model. Why Study the Relational Model? Linda Wu (CMPT )

Relational Model. Topics. Relational Model. Why Study the Relational Model? Linda Wu (CMPT ) Topics Relational Model Linda Wu Relational model SQL language Integrity constraints ER to relational Views (CMPT 354 2004-2) Chapter 3 CMPT 354 2004-2 2 Why Study the Relational Model? Most widely used

More information

CONCEPTUAL DESIGN: ER TO RELATIONAL TO SQL

CONCEPTUAL DESIGN: ER TO RELATIONAL TO SQL RELATIONAL MODEL TO Data Model CONCEPTUAL DESIGN: ER TO RELATIONAL TO How to represent Entity sets, Relationship sets, Attributes, Key and participation constraints, Subclasses, Weak entity sets...? 2

More information

The Relational Model 2. Week 3

The Relational Model 2. Week 3 The Relational Model 2 Week 3 1 We have seen how to create a database schema, how do we create an actual database on our computers? professor(pid : string, name : string) course(pid : string, number :

More information

Database Applications (15-415)

Database Applications (15-415) Database Applications (15-415) The Entity Relationship Model Lecture 2, January 12, 2016 Mohammad Hammoud Today Last Session: Course overview and a brief introduction on databases and database systems

More information

The Relational Model. Why Study the Relational Model? Relational Database: Definitions

The Relational Model. Why Study the Relational Model? Relational Database: Definitions The Relational Model Database Management Systems, R. Ramakrishnan and J. Gehrke 1 Why Study the Relational Model? Most widely used model. Vendors: IBM, Microsoft, Oracle, Sybase, etc. Legacy systems in

More information

Database Management Systems. Syllabus. Instructor: Vinnie Costa

Database Management Systems. Syllabus. Instructor: Vinnie Costa Database Management Systems Syllabus Instructor: Vinnie Costa vcosta@optonline.net CSC056-Z1 Database Management Systems Vinnie Costa Hofstra University 1 Course Description This course is designed to

More information

The Relational Model. Chapter 3

The Relational Model. Chapter 3 The Relational Model Chapter 3 Why Study the Relational Model? Most widely used model. Systems: IBM DB2, Informix, Microsoft (Access and SQL Server), Oracle, Sybase, MySQL, etc. Legacy systems in older

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

Introduction to Data Management. Lecture #4 E-R Model, Still Going

Introduction to Data Management. Lecture #4 E-R Model, Still Going Introduction to Data Management Lecture #4 E-R Model, Still Going Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke Today s Reminders Continue to

More information

The Relational Model. Chapter 3. Database Management Systems, R. Ramakrishnan and J. Gehrke 1

The Relational Model. Chapter 3. Database Management Systems, R. Ramakrishnan and J. Gehrke 1 The Relational Model Chapter 3 Database Management Systems, R. Ramakrishnan and J. Gehrke 1 Why Study the Relational Model? Most widely used model. Vendors: IBM, Informix, Microsoft, Oracle, Sybase, etc.

More information

The Relational Model (ii)

The Relational Model (ii) ICS 321 Fall 2009 The Relational Model (ii) Asst. Prof. Lipyeow Lim Information and Computer Science Department University of Hawaii at Manoa 1 Internet Book Store Example Isbn title author qty price year

More information

Database Systems. Course Administration

Database Systems. Course Administration Database Systems ( ) September 20, 2004 Lecture #2 By Hao-hua Chu ( ) 1 Course Administration Can everyone get the textbook? HW #1 is out on the course homepage It is due one week from today. Next week

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

CMPT 354 Database Systems I

CMPT 354 Database Systems I CMPT 354 Database Systems I Chapter 2 Entity Relationship Data Modeling Data models A data model is the specifications for designing data organization in a system. Specify database schema using a data

More information

High-Level Database Models (ii)

High-Level Database Models (ii) ICS 321 Spring 2011 High-Level Database Models (ii) Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa 1 Logical DB Design: ER to Relational Entity sets to

More information

The Relational Model. Chapter 3. Comp 521 Files and Databases Fall

The Relational Model. Chapter 3. Comp 521 Files and Databases Fall The Relational Model Chapter 3 Comp 521 Files and Databases Fall 2012 1 Why Study the Relational Model? Most widely used model by industry. IBM, Informix, Microsoft, Oracle, Sybase, etc. It is simple,

More information

ER to Relational Mapping. ER Model: Overview

ER to Relational Mapping. ER Model: Overview ER to Relational Mapping Davood Rafiei 1 ER Model: Overview The world is described in terms of Entities Relationships Attributes Constraints and Complications Key constraints Participation constraints

More information

Conceptual Design. The Entity-Relationship (ER) Model

Conceptual Design. The Entity-Relationship (ER) Model Conceptual Design. The Entity-Relationship (ER) Model CS430/630 Lecture 12 Slides based on Database Management Systems 3 rd ed, Ramakrishnan and Gehrke Relationship Set Representation ssn name lot since

More information

Review The Big Picture

Review The Big Picture CS445 - Introduction to Database Management Systems Fall Semester 2015 LECTURE 6 The Entity-Relationship Model Introduction TEXTBOOK REFERENCE: CHAPTERS 2,3 R&G 1 Review The Big Picture Data Modeling Relational

More information

CIS 330: Applied Database Systems. ER to Relational Relational Algebra

CIS 330: Applied Database Systems. ER to Relational Relational Algebra CIS 330: Applied Database Systems ER to Relational Relational Algebra 1 Logical DB Design: ER to Relational Entity sets to tables: ssn name Employees lot CREATE TABLE Employees (ssn CHAR(11), name CHAR(20),

More information

CSC 261/461 Database Systems Lecture 8. Spring 2018

CSC 261/461 Database Systems Lecture 8. Spring 2018 CSC 261/461 Database Systems Lecture 8 Spring 2018 Announcement Quiz No New Problem Set Study Chapter 5, 6, and 7 Go through the problem set Announcement Project 2 Part 1 Already out. Workshop covered

More information

Conceptual Design. The Entity-Relationship (ER) Model

Conceptual Design. The Entity-Relationship (ER) Model Conceptual Design. The Entity-Relationship (ER) Model CS430/630 Lecture 12 Slides based on Database Management Systems 3 rd ed, Ramakrishnan and Gehrke Database Design Overview Conceptual design The Entity-Relationship

More information

COMP 244. ER-Diagram Notations. Entity-Relationship Diagrams DATABASE CONCEPTS & APPLICATIONS. Database Concepts & Applications 1.

COMP 244. ER-Diagram Notations. Entity-Relationship Diagrams DATABASE CONCEPTS & APPLICATIONS. Database Concepts & Applications 1. COMP 244 DATABASE CONCEPTS & APPLICATIONS ER-Diagram Notations Attribute Key Attribute Multi-valued attributes Entity-Relationship Diagrams Derived Attribute Weak Entity Identifying Relationship 1 2 Database

More information

CSC 261/461 Database Systems Lecture 8. Fall 2017

CSC 261/461 Database Systems Lecture 8. Fall 2017 CSC 261/461 Database Systems Lecture 8 Fall 2017 Announcement Project 2 is out. Not a group project! CSC 261, Spring 2017, UR Agenda More about ER model ER model to Relation (Table) CSC 261, Spring 2017,

More information

From ER to Relational Model. Book Chapter 3 (part 2 )

From ER to Relational Model. Book Chapter 3 (part 2 ) From ER to Relational Model Book Chapter 3 (part 2 ) Logical DB Design: ER to Relational Translate Entity sets to tables: ssn name Employees lot CREATE TABLE Employees (ssn CHAR(11), name CHAR(20), lot

More information

COMP 244 DATABASE CONCEPTS & APPLICATIONS

COMP 244 DATABASE CONCEPTS & APPLICATIONS 1 COMP 244 DATABASE CONCEPTS & APPLICATIONS Entity-Relationship Diagrams 2 ER-Diagram Notations Attribute Key Attribute Multi-valued attributes Derived Attribute Weak Entity Identifying Relationship 3

More information

CSC 261/461 Database Systems Lecture 10

CSC 261/461 Database Systems Lecture 10 CSC 261/461 Database Systems Lecture 10 Spring 2018 Please put away all electronic devices Announcements From now on, no electronic devices allowed during lecture Includes Phone and Laptop Why? For your

More information

CS 146 Database Systems

CS 146 Database Systems DBMS CS 146 Database Systems Entity-Relationship (ER) Model CS 146 1 CS 146 2 A little history Progression of Database Systems In DBMS: single instance of data maintained and accessed by different users

More information

The Relational Model. Outline. Why Study the Relational Model? Faloutsos SCS object-relational model

The Relational Model. Outline. Why Study the Relational Model? Faloutsos SCS object-relational model The Relational Model CMU SCS 15-415 C. Faloutsos Lecture #3 R & G, Chap. 3 Outline Introduction Integrity constraints (IC) Enforcing IC Querying Relational Data ER to tables Intro to Views Destroying/altering

More information

Introduction to Data Management. Lecture #5 (E-R Relational, Cont.)

Introduction to Data Management. Lecture #5 (E-R Relational, Cont.) Introduction to Data Management Lecture #5 (E-R Relational, Cont.) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Announcements v HW#1 is due

More information

The Relational Model. Chapter 3. Comp 521 Files and Databases Fall

The Relational Model. Chapter 3. Comp 521 Files and Databases Fall The Relational Model Chapter 3 Comp 521 Files and Databases Fall 2014 1 Why the Relational Model? Most widely used model by industry. IBM, Informix, Microsoft, Oracle, Sybase, MySQL, Postgres, Sqlite,

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

Database Applications (15-415)

Database Applications (15-415) Database Applications (15-415) ER to Relational & Relational Algebra Lecture 4, January 20, 2015 Mohammad Hammoud Today Last Session: The relational model Today s Session: ER to relational Relational algebra

More information

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

The Relational Model. Roadmap. Relational Database: Definitions. Why Study the Relational Model? Relational database: a set of relations

The Relational Model. Roadmap. Relational Database: Definitions. Why Study the Relational Model? Relational database: a set of relations The Relational Model CMU SCS 15-415/615 C. Faloutsos A. Pavlo Lecture #3 R & G, Chap. 3 Roadmap Introduction Integrity constraints (IC) Enforcing IC Querying Relational Data ER to tables Intro to Views

More information

Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications. Problem. Faloutsos - Pavlo CMU SCS /615

Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications. Problem. Faloutsos - Pavlo CMU SCS /615 Faloutsos - Pavlo 15-415/615 Carnegie ellon Univ. Dept. of Computer Science 15-415/615 - DB Applications C. Faloutsos - A. Pavlo Lecture#2: E-R diagrams Problem Develop an application for U.G. admin: Student

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

Database Systems ( 資料庫系統 )

Database Systems ( 資料庫系統 ) Database Systems ( 資料庫系統 ) 9.28.2011 Lecture #3 1 Course Administration Please download HW #1 from course homepage It is due 10/12/2011. This lecture: R&G Chapter 3 Next week reading: R&G Chapter 41~ 4.1

More information

Problem. Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications

Problem. Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications Carnegie ellon Univ. Dept. of Computer Science 15-415/615 - DB Applications C. Faloutsos - A. Pavlo Lecture#2: E-R diagrams Problem Develop an application for U.G. admin: Student info Who--what class Class

More information

Introduction to Data Management. Lecture #4 (E-R à Relational Design)

Introduction to Data Management. Lecture #4 (E-R à Relational Design) Introduction to Data Management Lecture #4 (E-R à Relational Design) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Announcements v Reminders:

More information

Relational Databases BORROWED WITH MINOR ADAPTATION FROM PROF. CHRISTOS FALOUTSOS, CMU /615

Relational Databases BORROWED WITH MINOR ADAPTATION FROM PROF. CHRISTOS FALOUTSOS, CMU /615 Relational Databases BORROWED WITH MINOR ADAPTATION FROM PROF. CHRISTOS FALOUTSOS, CMU 15-415/615 Roadmap 3 Introduction Integrity constraints (IC) Enforcing IC Querying Relational Data ER to tables Intro

More information

Overview of Database Design Process Example Database Application (COMPANY) ER Model Concepts

Overview of Database Design Process Example Database Application (COMPANY) ER Model Concepts Chapter Outline Overview of Database Design Process Example Database Application (COMPANY) ER Model Concepts Entities and Attributes Entity Types, Value Sets, and Key Attributes Relationships and Relationship

More information

Administrivia. Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications. Course Topics. Problem

Administrivia. Carnegie Mellon Univ. Dept. of Computer Science /615 - DB Applications. Course Topics. Problem Faloutsos - Pavlo 15-415/615 Carnegie ellon Univ. Dept. of Computer Science 15-415/615 - DB Applications C. Faloutsos - A. Pavlo Lecture#2: E-R diagrams Administrivia Course url: http://15415.courses.cs.cmu.edu/

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

Introduction to Data Management. Lecture #6 E-Rà Relational Mapping (Cont.)

Introduction to Data Management. Lecture #6 E-Rà Relational Mapping (Cont.) Introduction to Data Management Lecture #6 E-Rà Relational Mapping (Cont.) Instructor: Mike Carey mjcarey@ics.uci.edu Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 It s time again for...

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

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

LECTURE 3: ENTITY-RELATIONSHIP MODELING

LECTURE 3: ENTITY-RELATIONSHIP MODELING LECTURE 3: ENTITY-RELATIONSHIP MODELING Ref. Chapter11 + Appendix F from Database Systems: A Practical Approach to Design, Implementation and Management. Thomas Connolly, Carolyn Begg. 1 IS220 : D a t

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

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

2. DatabaseDesign. Master I Software Engineering. Dr. Imed Bouchrika Dept of Mathematics & Computer Science University of Souk-Ahras

2. DatabaseDesign. Master I Software Engineering. Dr. Imed Bouchrika Dept of Mathematics & Computer Science University of Souk-Ahras 2. DatabaseDesign Master I Software Engineering Dr. Imed Bouchrika Dept of Mathematics & Computer Science University of Souk-Ahras imed@imed.ws Imed Bouchrika. Advanced Databases, Uni of Souk-Ahras 2013-2014

More information

Why Study the Relational Model? The Relational Model. Relational Database: Definitions. The SQL Query Language. Relational Query Languages

Why Study the Relational Model? The Relational Model. Relational Database: Definitions. The SQL Query Language. Relational Query Languages Why Study the Relational Model? The Relational Model Most widely used model. Vendors: IBM, Informix, Microsoft, Oracle, Sybase, etc. Legacy systems in older models E.G., IBM s IMS Recent competitor: object-oriented

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 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 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

SQL DDL. CS3 Database Systems Weeks 4-5 SQL DDL Database design. Key Constraints. Inclusion Constraints

SQL DDL. CS3 Database Systems Weeks 4-5 SQL DDL Database design. Key Constraints. Inclusion Constraints SQL DDL CS3 Database Systems Weeks 4-5 SQL DDL Database design In its simplest use, SQL s Data Definition Language (DDL) provides a name and a type for each column of a table. CREATE TABLE Hikers ( HId

More information

Conceptual Design with ER Model

Conceptual Design with ER Model Conceptual Design with ER Model Lecture #2 1/24/2012 Jeff Ballard CS564, Spring 2014, Database Management Systems 1 See the Moodle page Due February 7 Groups of 2-3 people Pick a team name Homework 1 is

More information

Translation of ER-diagram into Relational Schema. Dr. Sunnie S. Chung CIS430/530

Translation of ER-diagram into Relational Schema. Dr. Sunnie S. Chung CIS430/530 Translation of ER-diagram into Relational Schema Dr. Sunnie S. Chung CIS430/530 Learning Objectives Define each of the following database terms Relation Primary key Foreign key Referential integrity Field

More information