ERD for Employees, Manager, supervisor and budget

Construct an ERD for a company based on the following Business Rules:

  • Employee belongs to exactly one department

  • Department has one or many employees

  • A Manager takes care one or many budgets in the company.

  • Budgets are taken care of by only one manager.

  • Employees Have one Manager

  • Manager have one or many employees

  • Department is supervised by exactly one Supervisor

  • Supervisor supervises exactly one department

This is what I have done so far:

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