SELECT unit_of_measure FROM ref_product_categories WHERE product_category_code  =  "Herbs"
What is the unit of measuerment of the product category code "Herbs"?
SELECT unit_of_measure FROM ref_product_categories WHERE product_category_code = `` Herbs ''
select unit_of_measure from ref_product_categories where product_category_code = value
What is the unit of measuerment of the product category code `` Herbs '' ?