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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- Explain entity sets.arrow_forwardBy giving an example, define the following terms: A. Coding B. Relation and Relationshiparrow_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_forward
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- please explain elaboratlyarrow_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_forwardDefine Key Attribute with an example.arrow_forward
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