题解 | #计算总和#
计算总和
https://www.nowcoder.com/practice/d8a624021183454586da94d280cc8046
select
order_num,
sum(quantity * item_price) as total_price
from
OrderItems
group by
order_num
having
total_price >= 1000
order by
order_num
where和having的区别
1、having是查询返回结果之后，对结果进行过滤的
2、where是查询返回结果之前进行过滤的
3、在SQL中增加 HAVING 子句原因是，where关键字无法与聚合函数一起使用,having子句常跟group by一同使用，过滤分组后的数据
