ค้นหาวันที่สั่งซื้อของลูกค้าชื่อ "เจอรามี"
Find the dates of orders which belong to the customer named "Jeramie".
df_customers = pd.DataFrame(columns=['customer_id', 'customer_name']); df_orders = pd.DataFrame(columns=['date_order_placed', 'customer_id'])
df_customers.join(df_orders.set_index('customer_id'), on='customer_id')[df_customers['customer_name'] == 'Jeramie']['date_order_placed']