Build Mart entity relationship diagram models a complete e-commerce database schema with 13 core entities spanning customers, products, orders, and payments. Relationships connect Customer to Address, Cart, Review, and Order; Product to Brand, Category, Subcategory, and ProductImage; Order to OrderItem and Payment, forming a normalized relational structure. This schema demonstrates best practices for multi-tenant retail systems: separation of concerns, referential integrity, and support for complex queries on inventory, orders, and customer behavior. Fork this diagram on Diagrams.so to customize entity attributes, add new relationships, or export as SQL DDL for your database implementation. The design supports common e-commerce workflows including cart management, order fulfillment, and product reviews without redundancy.