Hello john M., thnaks by the answer.
I try your SQL code, and this only set 1,1 and the customer can buy 1 of all item in one category. This is not wath i want. I try to explain:
--- category 1
base1
base2
base3
Here you can buy only one base1 if you try to buy another virtuemart must show "You cant buy another".
--- category 2
add1
add2
add3
Here you can buy one of any product (this is fixed now, i set min and max to 1)
The problem is in the first category, i set 1,1 but you can add the 3 products to the cart, this isn't rigth.
I'm use ajax option to add products to the cart. May be its over there the solution, modify this code before close the cart. I'm not find where is this code or wath chage, i'm not a java programmer ;-).
Thank you again!
Oscar.