= Conceptual Design – ER Diagram and Data Requirements =

== ER Diagram ==
 

[[Image(OLPMS_ER_Diagram.png.png, width=300, link=OLPMS_ER_Diagram.png.png)]]



== Data Requirements ==

=== Entities ===

* **Users**
  * user_id (primary key)
  * first_name
  * last_name
  * email
  * password

* **Instructors**
  * instructor_id (primary key)
  * bio
  * expertise

* **Course**
  * course_id (primary key)
  * name
  * price
  * status

* **Enrollment**
  * enrollment_id (primary key)
  * enroll_date
  * completion_status
  * progress_percentage

* **Payment**
  * payment_id (primary key)
  * amount

* **SubscriptionPlan**
  * plan_id (primary key)
  * name
  * price
  * duration_months
  * access_type

* **Certificate**
  * certificate_id (primary key)
  * issue_date
  * certificate_code
  * status

=== Relationships ===

* A **User** can make multiple **Payments** (1:N)
* A **User** can enroll in multiple **Courses** through **Enrollment** (1:N)
* An **Instructor** can upload and manage multiple **Courses** (1:N)
* A **Course** can have multiple **Enrollments** (1:N)
* A **SubscriptionPlan** can be used by multiple **Users** (1:N)
* A **Certificate** is issued for a completed **Enrollment** (1:1)