Question

我试图计算从mysql查询中获得的值的差异，其中数据值是在TIME格式的竞争时间段中提取的。目标是获得每圈到达之间的单圈时间。这是表Times。

id            number            time
---------+----------------+--------------------
1               9               00:00:02.000000
2               10              00:00:14.000000
3               9               00:11:09.000000

Mysql

SELECT 
    t.number, count(*) as laps, 
    group_concat(time order by t.id separator ',' ) as times, 
    SEC_TO_TIME(SUM(TIME_TO_SEC(`time`))) as total
FROM 
    times t
GROUP BY 
    number 
ORDER BY 
    laps DESC, total ASC

此查询的输出为：

number        laps          times                     total
--------------------------------------------------------------
9              2           00:00:02,00:00:14         00:00:16.000000
10             1           00:11:09                  00:11:09.000000

现在，我需要的是获得每圈的时间长度，以及减法。有任何建议请。感谢这个结果：

number        laps          times                     total
--------------------------------------------------------------
9              2           00:00:02,00:00:12         00:00:14.000000
10             1           00:11:09                  00:11:09.000000

Answer 1

似乎你有总时间存储并且想要计算单圈时间。一种方法是使用子查询;

SELECT t.number, COUNT(1) laps, 
  GROUP_CONCAT(SEC_TO_TIME(time) ORDER BY t.id) times,
  SEC_TO_TIME(SUM(time)) total
FROM (
  SELECT t1.id, t1.number, 
    TIME_TO_SEC(t1.time) - COALESCE(SUM(TIME_TO_SEC(t2.time)), 0) time
  FROM times t1 
  LEFT JOIN times t2 ON t1.number = t2.number AND t2.id < t1.id
  GROUP BY t1.id, t1.number, t1.time
) t
GROUP BY number

子查询通过从每圈结束的总时间中减去id较小的相同数字的所有时间来计算单圈时间。外部查询以您正在寻找的格式对单圈时间进行格式化。

An SQLfiddle to test with

Mysql Group_concat和减法值

1 个答案: