Select rows with multiple tags… is there a better way?

Question

I am attempting to do a tag system for selecting products from a database. I have read that the best way to achieve this is via a many-to-many relationship as using LIKE \'%tag%

Answer 1

SELECT
    p.sku, p.name, p.path  
FROM
    shop_products p 
    INNER JOIN
    (
        SELECT A.sku FROM
        (
            SELECT product_sku sku FROM shop_products_categories
            WHERE category_id=(SELECT id FROM shop_categories WHERE path='flowers')
        ) A
        INNER JOIN
        (
            SELECT product_sku sku FROM shop_products_categories
            WHERE category_id=(SELECT id FROM shop_categories WHERE path='romance')
        ) B
        USING (sku)
    ) flowers_and romance
    USING (sku)
;

Make sure you have these indexes:

ALTER TABLE shop_categories ADD INDEX (path,id);
ALTER TABLE shop_categories ADD UNIQUE INDEX (path);
ALTER TABLE shop_products_categories ADD INDEX (product_sku,category_id);