数据表如下，按时间排序，按type分组。mysql中如何计算“排除最新一条之后，其余的num相加”？

Question

Answer 1

SELECT t.type, SUM(t.num)
FROM (
    SELECT type, num, ROW_NUMBER() OVER (PARTITION BY type ORDER BY time DESC ) AS row_num
    FROM C
) t
WHERE t.row_num != 1
GROUP BY t.type