I sell a product that has many standard lengths. ( 1 to Many)
I have a table for products e.g (48.3x3.2)
I have a table for the standard lengths stocked for each product. e.g (7500 or 10000 or 12000 or 15000mm)
a std order looks for example 48.3x3.2 / 10 lengths / 10000mm /price / del date/...