Database Concepts (8th Edition)
8th Edition
ISBN: 9780134601533
Author: David M. Kroenke, David J. Auer, Scott L. Vandenberg, Robert C. Yoder
Publisher: PEARSON
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Expert Solution & Answer
Chapter 4, Problem 4.14RQ
Explanation of Solution
Relationship:
An association between several entities is termed as relationship.
- It is used to link the attributes in entities.
- It is represented in a “diamond” box with name of the relationship in Entity-Relationship diagram.
The following diagram demonstrates the “relationship” among entities.
Degree of relationship:
Degree of relationship is a number of entity classes that participate in a relationship. The relationship can be divided into two ways based on the degree of the relationship...
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Chapter 4 Solutions
Database Concepts (8th Edition)
Ch. 4 - Prob. 4.1RQCh. 4 - Prob. 4.2RQCh. 4 - Prob. 4.3RQCh. 4 - What is a use case, and what is its purpose?Ch. 4 - Give an example of a data constraint.Ch. 4 - Prob. 4.6RQCh. 4 - Define the term entity, and give an example other...Ch. 4 - Explain the difference between an entity class and...Ch. 4 - Define the term attribute, and give examples for...Ch. 4 - Define the term identifier, and indicate which...
Ch. 4 - Prob. 4.11RQCh. 4 - Prob. 4.12RQCh. 4 - Prob. 4.13RQCh. 4 - Prob. 4.14RQCh. 4 - List and give an example of the three types of...Ch. 4 - Prob. 4.16RQCh. 4 - Prob. 4.17RQCh. 4 - Prob. 4.18RQCh. 4 - Define the term weak entity, and give an example...Ch. 4 - Explain the ambiguity in the definition of the...Ch. 4 - Define the term associative entity, and give an...Ch. 4 - Define the terms supertype, subtype, and...Ch. 4 - What is an exclusive subtype relationship? Give an...Ch. 4 - What is an inclusive subtype relationship? Give an...Ch. 4 - Prob. 4.25RQCh. 4 - Prob. 4.26RQCh. 4 - Prob. 4.27RQCh. 4 - Prob. 4.28RQ
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Similar questions
- Give an example of each of the following, other than those described in this chapter, and clearly explain why your example is this type of relationship and not of some other degree.a. ternary relationshipb. unary relationshiparrow_forwardER model relationships are represented using a.) relationship keys b.) primary keys c.) crows foot symbols d.) main keys What do the cardinalities in an ER model show, (please select all that apply)? a.) only a one to one relationship. b.) the minimum number of entities that can be involved in a relationship. c.) only a many to many relationship.arrow_forwardBy giving an example, define the following terms: A. Coding B. Relation and Relationshiparrow_forward
- Give an example of a ternary relationship (different from any example presented herein).arrow_forwardGiven the following ERD. ID name salary Instructor Grades teaches ID name salary Student 1) What is the descriptive attribute of the relationship between instructor and student? 2) Is this relationship a one-to-one, a one-to-many, or a many-to-many relationship?arrow_forwardConsider the following relation. Instructor (ID , name, dept – name, salary) Department (dept – name , building ,budget) Classroom (building , roomno , capacity ) Teaches (ID , course – id , sec – id , semesters ) Course (course – id , title , dept – name , credit ) Student (ID , name dept – name ,fot – ored ) Takes (ID , course – id , sec – id, semester , year, grade) Write down queries expressed in SQL. 1) Find the name of all instructors who got the highest salary in their department. 2) Find the names of all the students whose total credits are greater than 100. 3) Find the course id and grades of all courses taken by any student. 4) Find all departments that have at least one instructor, and list – the name of the departments along with the number of instructorarrow_forward
- Draw an Entity Relationship Diagram for all of those below. (a simple one) Each lecturer is identified by a unique number, name and phone. A lecturer teaches several courses, and for each course there is a unique code and title (not necessarily unique). There might be several lecturers in a course. Each course requires one or more text books. Each text book is used in at least one course. A text book is identified by a unique ISBN, and its title, authors, publisher and year of publication are known. Each course has a unique code. The bank has many customers. Every customer has at least one account with the bank. An account may be shared by several customers. Each customer has a unique number, type, the opening date and the balance. A flight carries many passengers on a specific airplane. Each airplane has a unique number, while each flight has a code (unique), destination and origin. A passenger has a name, passport number and nationalityarrow_forwardplease explain elaboratlyarrow_forwardGive examples of relations that are:(a) refl exive and symmetric but not transitive(b) refl exive and transitive but not symmetric(c) symmetric and transitive but not reflexivearrow_forward
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