题解 | #返回订单数量总和不小于100的所有订单的订单号#
返回订单数量总和不小于100的所有订单的订单号
https://www.nowcoder.com/practice/ff77e82b59544a15987324e19488aafd
SELECT order_num
FROM (
SELECT order_num, SUM(quantity)
FROM OrderItems
GROUP BY order_num
HAVING SUM(quantity) >= 100
) a
ORDER BY order_num
题解：
1.任务：查询订单号
2.限制：订单数量总和不低于100
3.排序
思路：
1.先写查询语句，查询订单号
2.要计算每个订单号的订单数量之和，使用sum函数和group by语句，
3.排序order by
