Question

Symbol Meaning ENTITY TYPE WEAK ENTITY TYPE RELATIONSHIP TYPE IDENTIFYING RELATIONSHIP TYPE ATTRIBUTE KEY ATTRIBUTE MULTIVALUED ATTRIBUTE COMPOSITE ATTRIBUTE DERIVED ATTRIBUTE TOTAL PARTICIPATION OF E? IN R CARDINALITY RATIO 1:N FOR E?:E? IN R STRUCTURAL CONSTRAINT (min, max) ON PARTICIPATION OF E IN R

          Symbol
Meaning
ENTITY TYPE
WEAK ENTITY TYPE
RELATIONSHIP TYPE
IDENTIFYING RELATIONSHIP TYPE
ATTRIBUTE
KEY ATTRIBUTE
MULTIVALUED ATTRIBUTE
COMPOSITE ATTRIBUTE
DERIVED ATTRIBUTE
TOTAL PARTICIPATION OF E? IN R
CARDINALITY RATIO 1:N FOR E?:E? IN R
STRUCTURAL CONSTRAINT (min, max) ON
PARTICIPATION OF E IN R

Show more…

Symbol
Meaning
ENTITY TYPE
WEAK ENTITY TYPE
RELATIONSHIP TYPE
IDENTIFYING RELATIONSHIP TYPE
ATTRIBUTE
KEY ATTRIBUTE
MULTIVALUED ATTRIBUTE
COMPOSITE ATTRIBUTE
DERIVED ATTRIBUTE
TOTAL PARTICIPATION OF E? IN R
CARDINALITY RATIO 1:N FOR E?:E? IN R
STRUCTURAL CONSTRAINT (min, max) ON
PARTICIPATION OF E IN R

Added by Timothy S.

Computer Science and Information Technology

Trishna Knowledge Systems 2018 Edition

Instant Answer

Solved by Expert Supreeta N

09/08/2023

Step 1

We have four entities: Department, Employee, Project, and Interest Group. Show more…

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Design an ER diagram for a company database: The company consists of many departments, and each department has a unique name, a location, a manager, and lots of employees. Each employee works for one specific department, and each employee has a unique id, a name, a position, and a salary. A department manager is also an employee, and an employee can lead at most one department. A project is hosted by one department (referred to as the host department), and other departments can collaborate on the same project (referred to as collaborating departments). Each project has a unique project number, a start date, and a deadline. Besides, the company has also set up several interest groups for many employees to join, and we keep track of the date when each employee joins it. Each interest group has a unique name, a capacity, and a single team leader who is also an employee. Each employee can join no or many interest groups but can lead at most one. Each interest group organizes several events. We keep track of the event location and event date for each event. Events from different interest groups may be conducted on the same day and at the same location. Draw the ER diagram and state any assumptions you make. But you should not add extra entities, attributes, or relationships beyond the above description.

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Transcript

00:01 Hello students, here is the entity and the attributes over here.

00:05 So, whereas the department with the attributes as the name, location and the manager id.

00:16 So, again the employee with its attribute as the name and the position salary id and it's the attributes of the employee table then with respect to the relationship it has with it is in a lead department that is the one -to -one with the department optional.

00:35 So, belong to the department one -to -one with the department.

00:38 Similarly, the project it has an attributes of the project number, date and the deadline.

00:44 So, these are the attributes and the host department id.

00:49 So, that is the foreign key referencing to the department.

00:53 Fine as with that the relation among with the department is the many -to -many with the department.

00:59 So, where the next comes the interest group.

01:02 So, here the attributes are the name, name is a unique and the capacity the team leader id the foreign key referencing the employee.

01:12 So, the relationship that organized the event one -to -many with the event belong to an employee one -to -many with the employee for the members.

01:22 So, lead by the employee one -to -one with the employee for the team leader.

01:27 So, whereas the event it has an attributes of the event location and the event date.

01:33 So, the relationship between it is an the part of the interest group one -to -many group...

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