ระบุชื่อของลูกค้าเฉพาะรายทั้งหมดที่ซื้อคีย์บอร์ด
List the names of all the distinct customers who bought a keyboard.
order_items_df = pd.DataFrame(columns=['order_id', 'product_id']); customers_df = pd.DataFrame(columns=['customer_name', 'customer_id']); products_df = pd.DataFrame(columns=['product_id', 'product_name']); customer_orders_df = pd.DataFrame(columns=['order_id', 'customer_id'])
df = customer_orders_df.merge(customers_df, on='customer_id').merge(order_items_df, on='order_id').merge(products_df, on='product_id'); df[df['product_name'] == 'keyboard']['customer_name'].unique()