题解 | #按城市对客户排序,如果城市为空,则按国家排序#
请按城市对客户进行排序,如果城市为空,则按国家排序
https://www.nowcoder.com/practice/c1b1d5bd008b4797ab2ef53a3afc4aba
select customer_id, gender, city, country, age, latest_place_order_date from customers_info order by case when city is not null then city else country end