✅ Let’s use this sample University System Scenario:
“A university has students, courses, professors, and departments.
Students enroll in courses.
Each course is taught by one professor.
Professors belong to one department.
Students have roll numbers, names, and emails.
Courses have course IDs and names.
Professors have IDs, names, and designations.
Departments have department IDs and names.”
🟩 Step 1: Entity Sets & Key Attributes
Entity | Key Attribute | Other Attributes |
|---|---|---|
| Roll No (PK) | Name, Email |
| Course ID (PK) | Course Name |
| Prof ID (PK) | Name, Designation |
| Dept ID (PK) | Dept Name |
🟨 Step 2: Relationships and Constraints
Relationship | Entities Involved | Cardinality | Participation |
|---|---|---|---|
| Student — Course | M:N | Partial |
| Professor — Course | 1:N (one prof → many courses) | Total (for Course) |
| Professor — Department | N:1 | Total |
🔷 Final ER Diagram Description:
Here's a textual representation of the diagram structure:
