题解 | #纠错3#
纠错3
https://www.nowcoder.com/practice/3870c9bca7a4406f899af3e903b8bf51
SELECT
order_num,
COUNT(order_num) AS items
FROM
OrderItems
GROUP by
order_num
HAVING
COUNT(items) >= 3
ORDER BY
items,
order_num;
分组按照 数据库中的字段 进行分组去重

