1, manufacturer product table: manufacturer information, product information (which manufacturers are saved and which products are provided)

2. Inventory table: inventory model, source customer, quantity and time.

3. Sales Form: Vehicle sales information

4. Purchase order form: purchase information (including purchased products, manufacturers, purchase date, payment date, amount, quantity, unit price, etc.).

5. Sales order: sales information (including all kinds of sales information, as above).

6. Customer Table: Save customer information.

7. Administrator table: operators and their permissions (one permission field is enough, such as "Purchasing | Customer Statistics").

That's basically all, seven tables, and there may be more tables for details.