dbdesign

User
#user_id
*name
*username/email
*password
*adress

Product
#product_id
*name
*description
*price
*category

//Basket_item
//#item_id
//*product_id
//*user_id

Sale
#sale_id
*user_id
*product_id
*date
*payment_type

Retailer
#retailer_id
*name
*telephone

Employee
#employee_id
*name
*email
*telephone
*adress
*birthdate
*occupation
*salary