SELECT unit_of_measure FROM ref_product_categories WHERE product_category_code  =  "Herbs"
Return the unit of measure for 'Herb' products.
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
Return the unit of measure for 'Herb ' products .