Stationery store entity-relationship diagram modeling customer transactions, product inventory, and supplier relationships. The schema connects CUSTOMER and EMPLOYEE to INVOICE, which links to INVOICE_LINE for itemized purchases, while PRODUCT tracks stock and connects to SUPPLIER via a junction table. This normalized design eliminates data redundancy, enforces referential integrity through primary and foreign keys, and supports complex queries on sales history, inventory levels, and supplier performance. Fork and customize this diagram to adapt it for your retail business logic, add additional attributes, or export as SQL DDL scripts. The mandatory relationships (solid lines) between INVOICE and its child tables ensure every sale is properly recorded with line items and employee attribution.