Entity-relationship diagram for a supermarket inventory and sales system with five core tables: User, Supplier, Product, Inventory, and Sale. Data flows from Suppliers through Products into Inventory stock levels, while Users process Sales that reference Products via Sale_Details line items. This schema demonstrates normalized database design for retail operations, separating transactional sales from inventory management and supplier relationships. Fork this diagram on Diagrams.so to customize for your supermarket chain, add additional entities like Returns or Promotions, or export as .drawio to integrate into your database documentation. The design supports real-time stock tracking and sales analytics essential for retail point-of-sale and inventory management systems.