id INT(11) not_null auto_increment comment(Primary key - unique identifier for each product-category recommendation link)
products_id INT(11) not_null comment(FK to products table - recommended product)
categories_id INT(11) not_null comment(FK to categories table - category where product is recommended)

--
primary id
idx_products_id products_id
idx_categories_id categories_id

##
engine innodb
character_set utf8mb4
collate utf8mb4_unicode_ci