Question: Find the product names that are colored 'white' but do not have unit of measurement "Handful".
SQL: SELECT t1.product_name FROM products AS t1 JOIN ref_product_categories AS t2 ON t1.product_category_code  =  t2.product_category_code JOIN ref_colors AS t3 ON t1.color_code  =  t3.color_code WHERE t3.color_description  =  "white" AND t2.unit_of_measure != "Handful"