Tài liệu Activity 5.1: Identifying Keys in the Logical Model pdf

Activity 5.1: Identifying Keys in the Logical Model In this activity, you will identify primary, foreign, and (if necessary) composite keys in the logical data model for Ferguson and Bardell, Inc. Objectives After completing this activity, you will be able to: ! Identify primary, foreign, and composite keys in a logical data model. ! Select a primary and foreign key type that is appropriate for a given entity. Before You Begin This activity will be completed individually, with a class discussion to follow. Time to complete this activity: 20 minutes 22 Activity 5.1: Identifying Keys in the Logical Model Exercise 1: Identifying Keys In this exercise, you will identify primary, foreign, and composite keys for a logical data model based on the Ferguson and Bardell, Inc. case study. ! Specify the keys in a logical data model 1. Review the ER diagram on the next page. 2. Identify the areas of the ER diagram for which keys are necessary. 3. Write the keys in the space provided on the ER diagram. 4. Label each key as necessary, using the following syntax: Primary Key: (PK) Foreign Key: (FK) Composite Key: (CK) Draw a line under the attributes used to define the composite key, and then label their types as Primary or Foreign. Next, you will discuss your answers with the class. Activity 5.1: Identifying Keys in the Logical Model 23 Name Address SSN E-Mail Type Salary BillableRate Employee EmployeeFirstName EmployeeLastName ClientName ClientLocation Date Expenses TotalHours BillableHours Description Timesheet ClientName ClientAddress ClientCity ClientState ClientZip Date Amount Work Description Invoice Name Address City State Zip Client Make Model VIN Year BeginMileage EndMileage MaintenanceCost1 MaintenanceDesc1 MaintenanceDate1 MaintenanceMiles1 MaintenanceCost2 MaintenanceDesc2 MaintenanceDate2 MaintenanceMiles2 MaintenanceCost3 MaintenanceDesc3 MaintenanceDate3 MaintenanceMiles3 Vehicle Is Issued Completes Is Made From Is Sent To Contracts With JobDesc TaskDesc Job Bills Time To Client Employee StartDate EndDate Description Contract Purchases 1 1 ∞ ∞∞ ∞ 1 0 ∞ ∞∞ ∞ 1 1 ∞ ∞∞ ∞ 0 ∞ ∞∞ ∞ 1 1 1 ∞ ∞∞ ∞ 1 1 ∞ ∞∞ ∞ 0 ∞ ∞∞ ∞ 0 ∞ ∞∞ ∞ THIS PAGE INTENTIONALLY LEFT BLANK . Time to complete this activity: 20 minutes 22 Activity 5. 1: Identifying Keys in the Logical Model Exercise 1: Identifying Keys In this exercise, you will. Activity 5. 1: Identifying Keys in the Logical Model In this activity, you will identify primary, foreign, and (if necessary) composite keys in the logical