CREATE TABLE products (product_name VARCHAR2, product_category_code VARCHAR2, color_code VARCHAR2)
CREATE TABLE ref_colors (color_code VARCHAR2, color_description VARCHAR2)
CREATE TABLE ref_product_categories (product_category_code VARCHAR2, unit_of_measure VARCHAR2)

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