Modern Database Management (12th Edition)
12th Edition
ISBN: 9780133544619
Author: Jeffrey A. Hoffer, Ramesh Venkataraman, Heikki Topi
Publisher: PEARSON
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Chapter 4, Problem 4.23RQ
Program Plan Intro
The conditions where a foreign key must not be null.
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Under what conditions must a foreign key not be null?
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Chapter 4 Solutions
Modern Database Management (12th Edition)
Ch. 4 - Prob. 4.1RQCh. 4 - Prob. 4.2RQCh. 4 - Prob. 4.3RQCh. 4 - Describe the primary differences between the...Ch. 4 - Summarize six important properties of relations.Ch. 4 - Describe two properties that each candidate key...Ch. 4 - Describe the three types of anomalies that can...Ch. 4 - Demonstrate each of the anomaly types with an...Ch. 4 - Fill in the blanks in each of the following...Ch. 4 - What is a well-structured relation? Why are...
Ch. 4 - Prob. 4.11RQCh. 4 - Describe how the following components of an E-R...Ch. 4 - Prob. 4.13RQCh. 4 - Prob. 4.14RQCh. 4 - Briefly describe four typical problems that often...Ch. 4 - Prob. 4.16RQCh. 4 - Explain how each of the following types of...Ch. 4 - Prob. 4.18RQCh. 4 - Prob. 4.19RQCh. 4 - Prob. 4.20RQCh. 4 - Prob. 4.21RQCh. 4 - What is the relationship between the primary key...Ch. 4 - Prob. 4.23RQCh. 4 - Explain what can be done with primary keys to...Ch. 4 - Prob. 4.25RQCh. 4 - Explain three conditions that suggest a surrogate...Ch. 4 - Prob. 4.27RQCh. 4 - For each of the following E-R diagrams from...Ch. 4 - Prob. 4.29PAECh. 4 - Prob. 4.30PAECh. 4 - For your answers to the following Problems and...Ch. 4 - Figure 4-3212 shows a class list for Millennium...Ch. 4 - Prob. 4.33PAECh. 4 - Prob. 4.34PAECh. 4 - Prob. 4.35PAECh. 4 - Prob. 4.36PAECh. 4 - Prob. 4.37PAECh. 4 - Prob. 4.38PAECh. 4 - For your answers to the following Problems and...Ch. 4 - Transform Figure 2-15a, attribute version, to 3NF...Ch. 4 - Prob. 4.41PAECh. 4 - Prob. 4.42PAECh. 4 - Prob. 4.43PAECh. 4 - Prob. 4.44PAECh. 4 - For your answers to Problem and Exercise 3-33 from...Ch. 4 - Prob. 4.46PAECh. 4 - Prob. 4.47PAECh. 4 - Figure 4-38 includes an EER diagram for a...Ch. 4 - Prob. 4.49PAECh. 4 - Prob. 4.50PAECh. 4 - Prob. 4.51PAECh. 4 - Prob. 4.52PAECh. 4 - Figure 4-40 shows an EER diagram for a university...Ch. 4 - Explore the data included in Table 4-9. Assume...Ch. 4 - Prob. 4.55PAECh. 4 - Prob. 4.56PAECh. 4 - Prob. 4.57PAECh. 4 - Prob. 4.58PAE
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- Why is a foreign key necessary to the database in order to guarantee its integrity? Is there a particular explanation for the significance of this?arrow_forwardWhy is a foreign key necessary to preserve the integrity of the database? Is there a reason for its significance?arrow_forwardHow does the foreign key contribute to the security of a database? Do you want to do this for a particular reason?arrow_forward
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