Modern Database Management
13th Edition
ISBN: 9780134773650
Author: Hoffer
Publisher: PEARSON
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Chapter 2, Problem 2.16RQ
Give an example of the use of effective (or effectivity) dates as attributes of an entity.
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Give an example of the use of effective (or effectivity) dates as attributes of an entity.
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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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- Data modeling is most often accomplished through the use of a(n) __________________. a. entity-relationship diagram b. data-flow diagram c. functional decomposition diagram d. activity diagramarrow_forwardWhat is the difference between a weak entity and a strong entity that is necessary to have a connection with another entity?arrow_forwardThe distinction between a weak and a strong entity set is best explained here.arrow_forward
- What does it mean to be a weak entity? Give an illustration.arrow_forwardWhat is NOT another name for an associative entity? Linking table Bridge entity Composite entity Strong entityarrow_forwardWhat differentiates a weak entity from a strong entity that is needed to have a connection with another entity is not immediately apparent.arrow_forward
- When an attribute of one entity type references another entity type's attribute, this means that: O it is a derived attribute O weak entity type exists O a relationship exists O it means nothingarrow_forwardb. Draw an Entity Relationship diagram from each of the following descriptions. Include the attributes, primary keys (underlines) and the relationships in the diagram (like relationship in Access). i. Each of the department has many employees assigned to it, but each employee works for only one department. if. A customer can rent many videotapes from the video store. Each of the videotapes can be rented to many customers.arrow_forwardWhat are the characteristics of a strong entity set as opposed to a poor one?arrow_forward
- For each entity, there needs to be an indication of whether it is one-to-one, one-to-many or many-to-many relationship. Here are the answers I have but I could use more guidance with it. I struggle with this type of question. BOOK and BOOK COPY (1:1) COURSE and COURSE-SECTION (M:N) COURSE-SECTION and ROOM (M:1) INSTRUCTOR and COURSE (1:M) ROOM and INSTRUCTOR (M:1)arrow_forwardFor each of the following pairs of related entities, indicate whether (under typical circumstances) there is a one-tomany or a many-to-many relationship. Then, using the shorthand notation introduced in the text, draw a diagram for each of the relationships.a. STUDENT and COURSE (students register for courses)b. BOOK and BOOK COPY (books have copies)c. COURSE and SECTION (courses have sections)d. SECTION and ROOM (sections are scheduled in rooms)e. INSTRUCTOR and COURSEarrow_forwardWhat is the concept in which the entity(variable) and its attributes(type) are associated during the execution time? Mention one of its disadvantage.arrow_forward
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