+----------------+       +------------------+       +---------------------+
|   Customer     |       |  Prescription    |       | Prescription_Detail |
+----------------+       +------------------+       +---------------------+
| PK CustomerID  |<------| PK PrescriptionID|------>| PK PrescriptionDetID|
| FirstName      |       | FK CustomerID    |       | FK PrescriptionID   |
| LastName       |       | IssueDate        |       | FK MedicineID       |
| Phone          |       | DoctorName       |       | Quantity            |
| ...            |       | Status           |       | Instruction         |
+----------------+       +------------------+       +---------------------+
                                                             |
                                                             |
+----------------+       +------------------+                |
| Sale_Transaction|       |   Medicine       |<---------------+
+----------------+       +------------------+
| PK SaleID      |------>| PK MedicineID    |
| FK CustomerID  |       | GenericName      |
| SaleDate       |       | BrandName        |
| TotalAmount    |       | FK SupplierID    |
+----------------+       | PricePerUnit     |
        |                | StockQuantity    |
        |                +------------------+
        |                         ^
        |                         |
        |                +------------------+
        |                |    Supplier      |
        |                +------------------+
        |                | PK SupplierID    |
        |                | CompanyName      |
        |                | Phone            |
        |                | ...              |
        |                +------------------+
        |
+----------------+
|  Sale_Detail   |
+----------------+
| PK SaleDetailID|
| FK SaleID      |
| FK MedicineID  |
| Quantity       |
| UnitPrice      |
+----------------+