[TYPO3-mvc] 1 to many relation

[Federico Bernardin]

Hi,
I develop a plugin with 2 entities:
category and product.
I need to know what is the category when a product is chosen and I need to know what are products related when one category is chosen.
The relation is 1 category many products.
I have created category property into product entity.

How can access the list of product when I know only category entity?
Should I create a property to map the relation between category and product in category entity?

Thanks
Federico