MySQL - 计算两个日期时间之间的净时差，同时排除中断？

In a MySQL query I am using the timediff/time_to_sec functions to calculate the total minutes between two date-times.

在MySQL查询中，我使用timediff / time_to_sec函数来计算两个日期之间的总分钟数。

For example:

例如：

2010-03-23 10:00:00
-
2010-03-23 08:00:00
= 120 minutes

What I would like to do is exclude any breaks that occur during the selected time range.

我想要做的是排除在所选时间范围内发生的任何中断。

For example:

例如：

2010-03-23 10:00:00
-
2010-03-23 08:00:00
-
(break 08:55:00 to 09:10:00)
= 105 minutes

Is there a good method to do this without resorting to a long list of nested IF statements?

有没有一种好方法可以在不使用一长串嵌套IF语句的情况下执行此操作？

UPDATE1:

UPDATE1：

To clarify - I am trying to calculate how long a user takes to accomplish a given task. If they take a coffee break that time period needs to be excluded. The coffee breaks are a at fixed times.

澄清 - 我试图计算用户完成给定任务所需的时间。如果他们喝咖啡休息时间，则需要排除时间段。咖啡休息时间是固定的。

1 个解决方案

#1

sum all your breaks that occur during the times, and then subtract to the result of the timediff/time_to_sec function

将所有在时间段内发生的中断加起来，然后减去timediff / time_to_sec函数的结果

SELECT TIME_TO_SEC(TIMEDIFF('17:00:00', '09:00:00')) -- 28800

SELECT TIME_TO_SEC(TIMEDIFF('12:30:00', '12:00:00')) -- 1800
SELECT TIME_TO_SEC(TIMEDIFF('10:30:00', '10:15:00')) -- 900

-- 26100

Assuming this structure :

假设这个结构：

CREATE TABLE work_unit (
 id INT NOT NULL,
 initial_time TIME,
 final_time TIME
)
CREATE TABLE break (
 id INT NOT NULL,
 initial_time TIME,
 final_time TIME
)
INSERT work_unit VALUES (1, '09:00:00', '17:00:00')
INSERT break VALUES (1, '10:00:00', '10:15:00')
INSERT break VALUES (2, '12:00:00', '12:30:00')

You can calculate it with next query:

您可以使用下一个查询来计算它：

SELECT *, TIME_TO_SEC(TIMEDIFF(final_time, initial_time)) total_time
, (SELECT SUM(
 TIME_TO_SEC(TIMEDIFF(b.final_time, b.initial_time)))
  FROM break b 
  WHERE (b.initial_time BETWEEN work_unit.initial_time AND work_unit.final_time) OR (b.final_time BETWEEN work_unit.initial_time AND work_unit.final_time)
 ) breaks 
FROM work_unit

#1