category_product
---------------
id_category
id_product
product
---------------
id_product
id_manufacturer
manufacturer
---------------
id_manufacturer
name
How would I create an SQL query so that it selects all the names from manufacturer when id_category is equal to something?
It's a straightforward inner join of the tables:
SELECT m.name, cp.id_category
FROM manufacturer as m
INNER JOIN product as p
ON m.id_manufacturer = p.id_manufacturer
INNER JOIN category_product as cp
ON p.id_product = cp.id_product
WHERE cp.id_category = 'some value'