Car rental database ERD modeling customer, vehicle, booking, invoice, and payment entities with enforced business rules. CUSTOMER records link to BOOKING and INVOICE, while BOOKING connects CUSTOMER and VEHICLE with rental dates and status tracking. INVOICE captures booking charges and triggers PAYMENT records tied to customer and invoice, ensuring payment-at-rent and 7-day maximum rental constraints. This normalized schema supports multi-vehicle fleet management, advance and immediate bookings, and complete audit trails from reservation through payment. Fork and customize this ERD on Diagrams.so to adapt vehicle categories, add rental locations, or extend payment workflows for your rental platform.