Use Crow's foot notation when creating the ERD

We keep data on all of our customers, each order, and each payment and the inventory of bicycles for sale and rent

Any given customer may have many orders, and each order may have many payments $($since some large orders need to be put on multiple cards, for instance$).$

For any payment: there can only be one order, and the order must exist for a payment to be entered.

Each payment must originate from only one customer.

A payment may be split between different methods $-$ for example cash, check credit card etc

For any order, there can only be one customer$--$and the customer must exist before an order is placed.

An given order can consist of just one type of transaction $-$ a sale or rental. It cannot have both.

A bicycle must exist in the inventory for it to be sold or rented

An order for a sale may be shipped to the customer or picked up by a customer