Chijohnz Supermarket's entity-relationship diagram models a complete purchasing and payment workflow connecting customers, staff, sales transactions, products, and payments. Customer and Staff entities link to Sale, which branches into Payment for transaction settlement and Sale_Product for line-item tracking, with Product providing inventory and pricing data. This normalized schema eliminates data redundancy while maintaining referential integrity across the retail transaction lifecycle. Fork this diagram on Diagrams.so to customize it for your supermarket chain, add additional entities like Suppliers or Discounts, or export as .drawio for database implementation. The design supports multi-product sales per transaction and tracks payment methods, making it suitable for both cash and card-based retail environments.