Relationships Explained

• User → Transactions: A user can have multiple transactions for course purchases.

• User → Certificates: A user can earn multiple certificates from completed courses.

• Course → Lessons: Each course has multiple lessons in sequence.

• Lesson → Content: Each lesson can include multiple content items such as videos or PDFs.

• User → Reviews: Users can leave multiple reviews on courses they have taken.

• Course → Reviews: Courses can have many reviews from different users.

+--------+          +-------------+          +----------+
|  User  |<-------->| Transaction |--------->|  Course  |
+--------+          +-------------+          +----------+
     |                     |                      |
     |                     |                      |
     |                     v                      v
     |               +-----------+          +---------+
     |               | Certificate|         |  Review |
     |               +-----------+          +---------+
     |                     ^
     |                     |
     |                     |
     v                     |
+--------+                 |
| Review |-----------------+
+--------+
     |
     v
+---------+
|  Course |
+---------+
     |
     v
+--------+
| Lesson |
+--------+
     |
     v
+---------+
| Content |
+---------+

• User connects to Transaction, Certificate, Review

• Transaction and Certificate link User and Course

• Course contains multiple Lessons

• Lesson contains multiple Content (videos/PDFs)

• Review links User and Course