php - select all products from child categories in parent category
I have the following 'categories' table:
Let's say I have the following 'products' table:
With the following query, I select all the products in a category:
Ok, my question:
The product 'Apple iPhone 8' is in the category Apple, this is a subcategory of the category Smartphones. If I replace the '?' in my query with 13 (the category ID of Apple), I get the product. When I replace the '?' in my query with 12 (the category ID of Smartphones), I don't get the product. I want to select all products that are in the category or in one of the child/grandchild/... categories. How can I do this with a single query (if possible)?