Assigning a product to multiple categories and searching through them PostgreSQL?

Question

PostgreSQL

Hello, I have a table with a product and a table with categories (there is an id of the parent category), how can I specify several categories in the table with products, so that I can find them later. For example, a product has categories 4, 8, 12 and I need to get this product if I search in categories 8, 15 or 8, 12. The
question is what data type to use to store the category id and convenient search, as well as , so that it would be possible to use combined queries and get the product and all categories, including parent ones, in one query?

Answer 1

one product belongs to several categories and one category belongs to several products (many-to-many relationship). Need a 3rd link table.
I would store records in this 3rd
table id_product, id_category
in this case, all product categories are pulled out through
All products in a category are pulled through

SELECT id_product FROM prod_cat WHERE id_category=xx

Answer 2

Look
here
. However, I myself use the link tables, as described above.