# What is the cardinality ratio for department:employee?

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Question 1:
The clinic has several dentists. Each dentist has a unique Number, name, nationality, multiple room-number, salary, birth-date and home-address (Box, City, Zip).
Each client (patient) has a unique Code, name, home-phone, work-phone, address, and birth-date. Each client is assigned to one dentist. All future visits will be to the same dentist. A client can be insured or self-paying. An insured client should have an insurance company-name, and company-Phone, while a self-paying client must have a bank-name and a bank account.
Each visit of a client is described by a date, type, action, fee, and date-of-next-appointment.

Design an ER diagram for the following Dental Clinic database. Your diagram should have all the needed details. You may make any reasonable assumptions but you have to state them clearly.
Design an Entity Relationship (ER) Model to represent the above requirements.
Convert the ER Diagram that presented in part-1 to Rational Schema.
Question 2 :
– Explain and distinct between disjoint and overlapping constraints.
Question 3:
Define Cardinality Ratios for binary relationship? What are possible Cardinality Ratios for Binary Relationship? Suppose in SEU, there are some departments consist of many employees.
What is the cardinality ratio for DEPARTMENT:EMPLOYEE?
Question 4:
In SEU, identify Cardinality ratios between the following entities:
Entity 1Cardinality RatioEntity 2
CLASSROOM______________PODIUM
STUDENT______________CLASS
INSTRUCTOR______________TECHNICAL STAFF
ROOM______________BRANCH
STUDENT______________TEACHER
INSTRUCTOR______________DEAN
——————————————
Requirements:
– no plagiarism.
– add references if its need.
– details.