id int not_null auto_increment comment(Primary key - unique identifier for each quantity discount rule)
products_id int not_null comment(FK to products table - product with quantity discount)
suppliers_id int  not_null comment(FK to suppliers table - supplier offering the discount)
customers_group_id int default(0) not_null comment(FK to customers_groups table - customer group eligible for discount, 0: all groups)
discount_quantity int not_null comment(Minimum quantity required to receive discount)
discount_supplier_price decimal(10,2) not_null comment(Supplier cost at this quantity level)
discount_customer decimal(10,2) not_null comment(Customer discount percentage or amount at this quantity level)
--
primary id
##
engine innodb
character_set utf8mb4
collate utf8mb4_unicode_ci