= Conceptual Design – ER Diagram and Data Requirements =

== ER Diagram ==
 

 


== Data Requirements ==

=== Entities ===

* **Users: Entity representing all users who access the platform (students / learners).**
  * User_ID – Primary key
  * First_Name – Varchar
  * Last_Name – Varchar
  * Email – Varchar(unique)
  * Password – Varchar

* **Administrators: Entity representing instructors who create and manage educational content.**
  * Admin_ID – Primary key
  * Admin_Level – varchar

* **Payment: Entity representing financial transactions.**
  * Payment_ID – Primary key
  * Amount – Decimal
  
* **Course: Entity representing the courses offered on the platform.**
  * Course_id – Primary key
  * Certificate – Varchar
  * Name – Varchar
  * Price – Decimal
  * status – Varchar

* **Enrollment: Entity representing the enrollment of a user in a course.**
  * Enrollment_id – Primary key
  * Enroll_date – Date
  * Completion_Status – Varchar
  * Progress_percentage – int

* **Payment: Entity representing financial transactions.**
  * Payment_ID – Primary key
  * Amount – Decimal

* **SubscriptionPlan: Entity representing available subscription plans.**
  * Plan_ID – Primary key
  * Name – Varchar
  * Price – Decimal
  * Duration_months – Int
  * Description – Varchar
  * Access_type – Varchar

* **Certificate: Entity representing certificates issued after course completion.**
  * Certificate_id – Primary key
  * Issue_date – Date
  * Certificate_code – Varchar
  * Status – Varchar

* **UserSubscription: Entity representing active subscriptions of users.**
  * Subscription_ID – Primary key
  * Start_date – Date
  * End_date – Date
  * Status – Varchar

* **SupportTicket: Entity representing user support requests.**
  * Ticket_ID – Primary key
  * Subject – Varchar
  * Description – Varchar
  * Status – Varchar
  * Created_at – Date

* **Category: Entity representing course classification.**
  * Category_ID – Primary key
  * Name – Varchar
  * Description – Varchar

* **Module: Entity representing logical subdivisions of a course.**
  * Мodule_id – Primary key
  * Тitle – Varchar
  * Description – Varchar
  
* **Lesson: Entity representing individual learning units.**
  * Lesson_ID – Primary key
  * Тitle – Varchar
  * Material – Varchar
 
* **Quiz: Entity representing assessments associated with lessons.**
  *  Quiz_ID – Primary key
  * Total_points – Int
  * Passing_score – Int

=== Relationships ===

* A **User** can make multiple **Payments** (1:N)