The Entity–Relationship (E‑R) Model, developed by Peter Chen in 1976, introduced a new way to represent data relationships. Which of the following best describes a key feature or purpose of this model?

In the E‑R Model, what is an entity?

In an E‑R model, which statement best defines a relationship?

Which of the following best describes an attribute in an E‑R diagram, and what is its notation?

What is the primary key in the context of an E‑R model?

Which of the following best defines cardinality in an E‑R model?

Which of the following best describes data modeling in an organization?

In the E‑R Model, which symbol represents an entity?

Which component of the E‑R Model describes the properties or characteristics of an entity?

What is the notation for a relationship in an E‑R diagram?

In data modeling, cardinality refers to:

Which of the following is an example of an entity in a university’s database?

Which of the following best demonstrates a relationship between entities?

Why is data modeling important for organizations?

A company wants to design a database to track its employees and the departments they belong to. The design team identifies “Employee” and “Department” as major elements in the model. What do these elements represent in the E‑R model?

In a university database, each professor can teach several courses, and each course can be taught by only one professor. The link between “Professor” and “Course” represents what component of an E‑R model?

A retail store is designing a database to store customer information such as Customer_ID, Name, Address, and Phone Number. In this scenario, which element would best represent an attribute?

A hospital database needs to ensure that every patient record is unique. The designer decides to use “Patient_ID” as a special field for that purpose. What is “Patient_ID” in the context of the E-R model?

A college database shows that each student can enroll in many courses, and each course can have many students. What type of relationship exists between “Student” and “Course”?

In an Enhanced ER Model, a supertype represents:

A subtype in an EER diagram is:

The relationship between a supertype and its subtypes is known as:

Which constraint ensures that an entity instance of a supertype belongs to only one subtype?

The completeness constraint specifies whether:

Scenario 1: University Database Situation: A university keeps records of all people associated with it. The database includes Students, Professors, and Staff. All share common attributes: PersonID, Name, DateOfBirth. Each subtype has unique attributes: • Student: Major, Year • Professor: Department, ResearchArea • Staff: Position, WorkShift Each person must belong to exactly one category. Identify the supertype.

Scenario 1: University Database Situation: A university keeps records of all people associated with it. The database includes Students, Professors, and Staff. All share common attributes: PersonID, Name, DateOfBirth. Each subtype has unique attributes: • Student: Major, Year • Professor: Department, ResearchArea • Staff: Position, WorkShift Each person must belong to exactly one category. Identify the subtypes.

Scenario 1: University Database Situation: A university keeps records of all people associated with it. The database includes Students, Professors, and Staff. All share common attributes: PersonID, Name, DateOfBirth. Each subtype has unique attributes: • Student: Major, Year • Professor: Department, ResearchArea • Staff: Position, WorkShift Each person must belong to exactly one category. What is the disjointness constraint here?

Scenario 2: Vehicle Database Situation: A transport company maintains a database of Vehicles, classified as Cars and Trucks. All vehicles share VehicleID, Model, Year. • Car: PassengerCapacity • Truck: LoadCapacity A vehicle can be either a car or a truck, but not both. Identify the supertype.

Scenario 2: Vehicle Database Situation: A transport company maintains a database of Vehicles, classified as Cars and Trucks. All vehicles share VehicleID, Model, Year. • Car: PassengerCapacity • Truck: LoadCapacity A vehicle can be either a car or a truck, but not both. Which type of specialization is this?

A company wants to design a database to track employees and the projects they work on. Each employee can work on multiple projects, and each project can have multiple employees. Which relational design principle should be applied to avoid redundancy?

A database stores student information, including student ID, name, and courses enrolled. The database allows duplicate student IDs. Which rule of relational databases is being violated?

A library database has tables for Books, Authors, and Publishers. A book can have multiple authors, and an author can write multiple books. To implement this properly, which relational structure should be used?

A retail company notices that their Customer table contains repeated addresses for the same customer. What normalization step should be applied to reduce redundancy?

In a university database, each course must belong to a department. If a course is deleted but its department remains, which type of referential integrity rule is being applied?

A database designer notices that some tables contain repeating groups of columns (like Phone1, Phone2, Phone3). Which normalization principle is being violated?

In a relational model, the primary key of a table uniquely identifies each record. A database designer wants to ensure that no two orders have the same order ID. Which type of integrity should be enforced?

An e-commerce database has Orders and Customers tables. Each order must belong to a customer. Which relational database concept ensures that an order cannot exist without a customer?

In a hospital database, the table Patient contains PatientID, Name, and Address. The Address field contains Street, City, State, and Zip all in one column. Which design problem is present?

A company wants to track which employees manage which departments. One employee can manage only one department, and each department has only one manager. Which type of relationship is this?

A table contains OrderID, ProductID, and Quantity. The same OrderID appears multiple times for different products. Which concept allows this design without violating the relational model?

In a sales database, the designer wants to prevent negative quantities in the Orders table. Which database feature should be used?

A library database has a table Book with ISBN as the primary key. The same ISBN is mistakenly entered twice. What problem has occurred?

A university wants to store students' elective courses. Students can choose multiple electives, and electives can be chosen by multiple students. Which relational design should be implemented?

A database designer wants to eliminate transitive dependencies in a table containing EmployeeID, DepartmentID, DepartmentName, and Manager. Which normalization form should be applied?

In a relational database, a foreign key references a primary key in another table. What does this enforce?

A table stores CustomerID, OrderID, and OrderDate. To uniquely identify each row, the designer decides to use both CustomerID and OrderID as a key. What type of key is this?

A database contains a table Employee with EmployeeID and ManagerID. The ManagerID refers to another EmployeeID in the same table. What kind of relationship is this?

A table contains StudentID, CourseID, and InstructorID. An instructor can teach multiple courses, but each course has only one instructor. What type of dependency exists between CourseID and InstructorID?

A designer notices that multiple tables in a database have the same combination of attributes duplicated across them. Which design principle can reduce this redundancy?