组合两个查询，这两个查询都根据结果对数据进行分类

SELECT order_number, customer_name, order_date, order_amount
FROM orders
WHERE order_amount > 1000 -- 高金额订单条件

SELECT order_number, customer_name, order_date, order_amount
FROM orders
WHERE order_date > '2022-01-01' -- 近期订单条件

SELECT order_number, customer_name, order_date, order_amount,
       CASE
           WHEN order_amount > 1000 AND order_date > '2022-01-01' THEN '高金额近期订单'
           WHEN order_amount > 1000 AND order_date <= '2022-01-01' THEN '高金额过去订单'
           WHEN order_amount <= 1000 AND order_date > '2022-01-01' THEN '低金额近期订单'
           WHEN order_amount <= 1000 AND order_date <= '2022-01-01' THEN '低金额过去订单'
           ELSE '其他'
       END AS order_category
FROM orders