Broadway Entertainment Co., Inc. Case Question Solutions Essay

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Broadway Entertainment Co., Inc. Case Question Solutions Essay

1. Review the information flow diagrams you developed for inquiries in the BEC instance at the terminal of Chapter 5 ( or plot given to you by your instructor. ) Study the information flows and informations shops on these diagrams and make up one’s mind if you agree with the team’s decision that there are merely the six entity types listed in this instance and in BEC Figure 6-1. If you disagree. define extra entity types. explicate why they are necessary. and modify BEC Figure 6-1. The six entity types in BEC Figure 1 are the lone 1s needed to stand for the MyBroadway system. However. depending on what informations about Customers and Employees are required. entities for these objects may besides be required. 2. Again. reexamine the DFDs you developed for the MyBroadway system ( or those given to you by your teacher ) . Use these DFDs to place the properties of each of the six entities listed in this instance plus any extra entities identified in your reply to Question 1. Write an unambiguous definition for each property. Then. redraw BEC. Figure 6-1 by puting the six ( and extra ) entities in this instance on the diagram along with their associated properties. The updated ERD appears in the BEC ERD at the terminal of this subdivision. Microsoft Visio was used to fix the ERD. The Comment entity has the properties:

* Comment ID – a figure generated by the system to unambiguously place a remark. * Membership ID – the rank figure of the client who makes the remark. * Member Comment – the text that a client states about a certain merchandise. * Member Name – the name of the client who makes the remark. * Comment Time Stamp – the day of the month and clip that the remark was entered into the system by a client. * Parent/Child – a appellation whether the client come ining the remark is a parent or a kid. * Product ID – serves as a foreign key.

The Pick entity has the properties:

* Pick ID – a figure generated by the system to unambiguously place an employee choice. * Employee Comment – the text that an employee provinces about a certain merchandise. * Rating – a structured evaluation given to a certain merchandise by an employee. * Employee ID – the ID figure of the employee who submitted the choice. * Employee Name – the name of the employee who entered the choice into the system. * Pick Time Stamp – the day of the month and clip that the employee entered the choice into the system. * Product ID – serves as a foreign key.

The Product entity has the properties:

* Product ID – a figure generated by the system to unambiguously place a merchandise offered for sale or rent by BEC. * Title – the rubric of the merchandise. * Artist – the name of the creative person of the merchandise ( if applicable ) . * Type – an indicant if the merchandise is music. a game. or a film. * Publisher – the name of the publishing house of the merchandise. * Category – the class that the merchandise falls under ( comedy. play. etc. ) . * Media – the type of media that the merchandise is on ( Cadmium. DVD. etc. ) . * Description – a description of the merchandise.

* Release Date – the day of the month that the merchandise was released.
* Sale Price – the gross revenues monetary value of the merchandise.
* Rental Price – the rental monetary value of the merchandise.

The Request entity has the properties:

* Request ID – a figure generated by the system to unambiguously place petitions made by clients. * Request Time Stamp – the day of the month and clip that the petition was made by a client. * Membership ID – the rank ID figure of the client who made the petition. * Member Name – the name of the client who made the petition. * Artist – the name of the creative person ( if applicable ) of the merchandise being requested. * Title – the rubric of the merchandise being requested.

* Type – an indicant if the requested merchandise is music. a game. or a film. * Media – the type of media the client would wish the merchandise on. * Product ID – serves as a foreign key.

The Rental entity has the properties:

* Rental ID – a figure generated by the system to unambiguously place a lease of a specific merchandise by a client. * Membership ID – the rank ID figure of the client who rented the merchandise.

* Member

Name – the name of the individual who rented the merchandise. which may be different than the cardholder’s name ( kid. partner. etc. ) . * Rental Time Stamp – the day of the month that a client rented the merchandise involved in this lease. * Due Date – the day of the month that the rented merchandise is due back. This may be changed with a rental extension petition. * Returned? – an indicant if the rented point was returned or non. * Product ID – serves as a foreign key.

The Sale entity has the properties:

* Sale ID – a figure generated by the system to unambiguously place a sale of a specific merchandise to a client. * Membership ID – the rank ID figure of the client who purchased the merchandise. * Member Name – the name of the individual who purchased the merchandise. which may be different than the cardholder’s name ( kid. partner. etc. ) * Sale Time Stamp – the day of the month and clip that the merchandise was purchased by the client. * Product ID – serves as a foreign key.

3. Using your reply to Question 2. designate which property or attributes form the identifier for each entity type. Explain why you chose each identifier. Comment ID and Pick ID are the identifiers of the entities Comment and Pick. severally. because it would be much simpler to utilize a figure than a long twine of text. even though the remarks themselves will most probably be alone. Product ID is the identifier of the entity Product because it is possible that more than one merchandise could hold the same rubric. Request ID is the identifier of the entity Request because a client could do more than one petition for a merchandise on a certain twenty-four hours. Sale ID and Rental ID are the identifiers of the entities Sale and Rental. severally. because a client could purchase or lease more than one merchandise on a certain twenty-four hours.

4. Using your reply to Question 3. draw the relationships between entity types needed by the system. Remember. a relationship is needed merely if the system wants informations about associated entity cases. Give a meaningful name to each relationship. Specify cardinalities for each relationship and explicate how you decided on each lower limit and maximal cardinality on each terminal of each relationship. State any premises you made if the BEC instances you have read so far and the replies to inquiries in these instances do non supply the grounds to warrant the cardinalities you choose. Redraw your concluding E-R diagram in Microsoft Visio.

The relationships between Product and Comment. Pick. Request. Rental. and Sale are all one-to-many relationships. A Merchandise may hold zero or many Remarks. Choices. Leases. and Gross saless associated with it. Remarks. Choices. Requests. Leases. and Gross saless must hold one and merely one Product associated with them. Requests may non hold a Product associated with them ( until the merchandise goes into stock list ) . A suggested ERD is provided at the terminal of this subdivision.

5. Now that you have developed in your reply to Question 4 a complete E-R diagram for the MyBroadway database. what are the effects of non holding client or employee entity types on this diagram? Assuming merely the properties you show on the E-R diagram. would any attribute be moved from the entity it is presently associated with to a client or employee entity type if such entity types were on the diagram? Why or why non? The effect of non including the client and employee entity types on this diagram is that names ( and perchance other properties ) appear as an property on several of the other entities. I would travel the Member Name property from the Sale. Rental. Comment. and Request entities to the Customer entity and the Employee Name property from the Pick entity to the Employee entity if the Customer and Employee entities existed on this diagram.

This would extinguish the duplicate of informations. 6. Write undertaking dictionary entries ( utilizing criterions given to you by your teacher ) for all the entities. properties. and relationships shown in the E-R diagram in your reply to Question 4. How elaborate are these entries at this point? What other inside informations still must be filled in? Are any of the entities on the E-R diagram in your reply to Question 4 weak entities? Why? In peculiar. is the REQUEST entity type a weak entity. If so. why? If non. why non? Answers to this inquiry will change due to specific teacher instructions. Typical dictionary contents for entity. property. and relationship objects are listed below.

Entity: Short name. name. plural. volume ( initial. upper limit. norm. growing rate ) . informations warehouse type. list of properties. description Attributes: Primary UID. optional? . per centum used ( initial. norm ) . sphere. type. maximal length. mean length. denary topographic points. units. derivation. on status. void value. default. sequence in kind. kind order Relationships: From entity name. from relationship name. from optionality and grade. to entity name. to relationship name. to optionality and grade. description

7. What date-related attributes did you place in each of the entity types in your reply to Question 4? Why are each of these needed? Can you do some general observations about why day of the month attributes must be kept in a database based on your analysis of this database? The Sale. Rental. Comment. Pick. and Request entities all have date/time-related entities. The date/time properties are needed because the same client could notice on. rent. purchase. or petition. the same merchandise ( on the same twenty-four hours ) . and an employee could come in a choice of the same merchandise more than one time ( on the same twenty-four hours ) . Besides. to archive old. disused informations. or to see temporal tendencies. day of the months are needed.