Database Design Using ER/EER Data Model

Suppose that you find a job in the Human Resources Department of The DreamCompany.
You are responsible for building a database to store various information about the employees,
departments, and so on. In this part of the project, you will complete a conceptual design using
ER/EER data model for a much simplifed HR database based on the following set of requirements:

• The employees work in departments for some projects.
• An employee can work on multiple projects that may be participated by several departments.
  
• Any employee can only be either a salariedEmp or an hourlyEmp but not both. An employee is uniquely identified by a ssn. We should record dob(date of birth), name, sex, and address of the employee. Name is composed of Fname, Minit, and Lname.
• A salariedEmp has a monthly salary and an hourlyEmp has a rate of hourPay.
• An employee may have dependents (described by name, sex, and relationship). Dependents of different employees may have the same names.
  
• Each department, identified by deptNum, has deptName and one or more locations. The numEmp (number of employees) can be regarded as a calculated attribute of the department.
• A department has a manager who has a officeNum and a startDate.
  
• A project is identified by projName and projNum together. It has a description (projDesc).

Please draw a ER/EER diagram. Be sure that your diagram includes composite and multi-valued attributes, ternary relationship and weak entity, and EER part of generalization. 

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