want to add a shopping cart table, let users add items to the shopping cart, click settlement to generate the order, but do not know how to design and associate
< H2 > reference < / H2 > the link I referenced
https://blog.csdn.net/wgyscsf.
customer(): cidcnamecphonecaddress
merchant():midmnamemphonemaddress
product():pidpnameppricepremainmid
order():oidodatetimeostateosummoneycid
orderitem():oiidiobuynumiosummoneypidoid