Modern Database Management
13th Edition
ISBN: 9780134792293
Author: Hoffer
Publisher: PEARSON
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Textbook Question
Chapter 2, Problem 2.23PAE
A cellular operator needs a
Can a customer have an unlimited number of plans?- Can a customer exist without a plan?
- Is it possible to create a plan without knowing who the customer is?
- Does the operator want to limit the types of handsets that can be linked to a specific plan type?
- Is it possible to maintain data regarding a handset without connecting it to a plan?
- Can a handset be associated with multiple plans?
- Assume a handset type exists that can utilize multiple operating systems. Could this situation be accommodated within the model included in Figure 2-24?
- Is the company able to track a manufacturer without maintaining information about its handsets?
- Can the same
operating system be used on multiple handset types? - There are two relationships between Customer and Plan. Explain how they differ.
- Characterize the degree and the cardinalities of the relationship that connects Customer to itself. Explain its meaning.
- Is it possible to link a handset to a specific customer in a plan with multiple customers?
- Can the company track a handset without identifying its operating system?
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A cellular operator needs a database to keep track of its
customers, their subscription plans, and the
handsets (mobile phones) that they are using. The E-
R diagram in Figure 2-24 illustrates the key entities
of interest to the operator and the relationships
between them. Based on the figure, answer the
following questions and explain the rationale for
your response. For each question, identify the
element(s) in the E-R diagram that you used to
determine your answer. a. Can a customer have an
unlimited number of plans?
b. Assume a handset type exists that can utilize
multiple operating systems. Could this situation
be accommodated within the model included in
Figure 2-24?
c. Is the company able to track a manufacturer
without maintaining information about its
handsets?
d. Can the same operating system be used on
multiple handset types?
e. There are two relationships between Customer
and Plan. Explain how they differ.
Create an ERD Diagram with all the relationships based of this:
The city of California has just established its criminal justice/police department. You and your team have been assigned the task of creating a database system for the department. The database should be able to store and manage information about the department's workers, their roles, medical records, and incidents that occurred under the department's jurisdiction. This includes information about the investigator(s), the offender(s), the evidence, and the judicial proceedings, such as the trial details, the presiding judge, and the lawyers. The database should also be able to support the recording of punishments, such as sentencing time, fines, and warnings.
Design a representation of the data in terms of entities , attributes and relationships between entities . Construct an E - R diagram to depict this representation . Show the cardinalities and all necessary information . Draw the solution on a piece of paper . Add your name and Upload you file here . You are asked to design a database for a sales company which needs to keep track of its sales orders in addition to employees ' information . 1- The company has salespersons . For each Salesperson , we need to know his ssn , name , date of start at work , address and phone number.2- A sales person plays the role of an agent for customers.3- A customer has only one agent , but the same salesperson can be an agent for several customers . Customers are identified by their emails . The company also stores a customers ' name , address , phone number and birthdate . 4- Customers place orders . Each customer can place many orders . 5- Orders are identified by their serial number , issuance date…
Chapter 2 Solutions
Modern Database Management
Ch. 2 - Define each of the following terms: entity type...Ch. 2 - Match the following terms and definitions....Ch. 2 - Contrast the following terms: stored attribute;...Ch. 2 - Prob. 2.4RQCh. 2 - Prob. 2.5RQCh. 2 - Prob. 2.6RQCh. 2 - State six general guidelines for naming data...Ch. 2 - Prob. 2.8RQCh. 2 - Prob. 2.9RQCh. 2 - State three conditions that suggest the designer...
Ch. 2 - List the four types of cardinality constraints,...Ch. 2 - Give an example, Other than those described in...Ch. 2 - What is the degree of a relationship? List the...Ch. 2 - Give an example (Other than those described in...Ch. 2 - Give an example of each of the following, other...Ch. 2 - Give an example of the use of effective (or...Ch. 2 - State a rule that says when to extract an...Ch. 2 - Prob. 2.18RQCh. 2 - In addition to explaining what action is being...Ch. 2 - For the Manages relationship in Figure 2-12a,...Ch. 2 - Explain the distinction between entity type and...Ch. 2 - Why is it recommended that every ternary...Ch. 2 - A cellular operator needs a database to keep track...Ch. 2 - Prob. 2.24PAECh. 2 - Answer the following questions concerning Figure...Ch. 2 - Prob. 2.26PAECh. 2 - You may have been assigned a CASE or a drawing...Ch. 2 - Consider the two E-R diagrams in Figure 2-25 Q,...Ch. 2 - Prob. 2.29PAECh. 2 - Are associative entities also weak entities? Why...Ch. 2 - Because Visio does not explicitly show associative...Ch. 2 - Figure 2-26 shows a grade report that is mailed to...Ch. 2 - Prob. 2.33PAECh. 2 - The Is Married To relationship in Figure 2-12a...Ch. 2 - Figure 2-27 represents a situation of students who...Ch. 2 - Figure 2-28 shows two diagrams (A and B), both of...Ch. 2 - Prob. 2.37PAECh. 2 - Review Figure 2-8LQ and Figure 2-22. Identify any...Ch. 2 - Prob. 2.39PAECh. 2 - Prob. 2.40PAECh. 2 - Prob. 2.41PAECh. 2 - Prob. 2.42PAECh. 2 - Prob. 2.43PAECh. 2 - Prob. 2.44PAECh. 2 - Prob. 2.45PAECh. 2 - Prob. 2.46PAECh. 2 - Prob. 2.47PAECh. 2 - Prob. 2.48PAECh. 2 - Draw an ERD for the following situation. (State...Ch. 2 - Prob. 2.50PAECh. 2 - Prob. 2.51PAECh. 2 - Review your answer to Problem and Exercise 2-49 if...
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