Lab3.pptx - LAB 3 INSTRUCTIONS AND SEVERAL OTHER DESIGN...

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LAB 3 INSTRUCTIONS AND SEVERAL OTHER DESIGN CASES
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Modeling is hard … Unfamiliar with the scenario Entities being too abstract Not all things go into the model More ERDs help Be patient! Things we learn will fall into their place, and start to make sense!!
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Problem 1 from Chapter 4 A department employs many employees, but each employee is employed by one department. Some employees, known as “rovers,” are not assigned to any department. A division operates many departments, but each department is operated by one division. An employee may be assigned many projects, and a project may have many employees assigned to it. A project must have at least one employee assigned to it. One of the employees manages each department, and each department is managed by only one employee. One of the employees runs each division, and each division is run by only one employee.
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Problem 1 from Chapter 4 A department employs many employees, but each employee is employed by one department. Some employees, known as “rovers,” are not assigned to any department. 1:M between DEPARTMENT-EMPLOYEE [DEPARTMENT is optional to EMPLOYEE] A division operates many departments, but each department is operated by one division. 1:M between DIVISION-DEPARTMENT An employee may be assigned many projects, and a project may have many employees assigned to it. A project must have at least one employee assigned to it. M:N between PROJECT-EMPLOYEE [EMPLOYEE is mandatory to PROJECT] One of the employees manages each department, and each department is managed by only one employee. 1:1 between DEPARTMENT-EMPLOYEE One of the employees runs each division, and each division is run by only one employee. 1:1 between DIVISION-EMPLOYEE
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One way to do it that correctly represents the business rules for this problem. Note this is not the only way. Many assumptions were made concerning the relationship participation.
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Problem 9 from Chapter 4 A friend of yours has opened Professional Electronics and Repairs (PEAR) to repair smartphones, laptops, tablets, and MP3 players. She wants you to create a database to help her run her business. When a customer brings a device to PEAR for repair, data must be recorded about the customer, the device, and the repair. The customer’s name, address, and a contact phone number must be recorded (if the customer has used the shop before, the information already in the system for the customer is verified as being current). For the device to be repaired, the type of device, model, and serial number are recorded (or verified if the device is already in the system). Only customers who have brought devices into PEAR for repair will be included in this system [mandatory participation, both ends] .
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  • Spring '19
  • Dr. Bin Li
  • Database, Homework, lab, Assignment, Database Concepts, Entity-relationship model, Telephone number

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