查找MySQL数据库中不同行中时间戳之间的重叠，按天数和ID分组

Question

我有一个表，其中列出了某些对象的事件。

有两个事件：“移动”和“加载”。他们可以开始和结束，而这些事件发生时会列出时间戳。

用下面的要求，我可以得到以下值：

sum of time, when movement took place (value in the fiddle: 421) 
sum of time, when load took place (value in the fiddle: 520) 
sum of time, when movement and load took place (value in the fiddle: 391) 

当前版本的每一天计算这些数字，这工作正常。

http://sqlfiddle.com/#!2/518dd/1

，但我也将有不同的ID。我现在要计算每个日期和每个ID的这些数字。当我加入这个数据，它崩溃，看到这个小提琴：

http://sqlfiddle.com/#!2/b43fa/6

这不是重复这个问题：Find intersections between rows and timestamps in a mysql db，因为解决这个问题是不适合/适应在这种情况下。

Answer 1

如图所示由Gordon，分组通过移动成为可能过滤到最外面的SELECT。 对于需要封闭运动事件的加载事件的搜索是在相同的方式完成在earlier answer：

SELECT id, 
     date(timestamp, 'unixepoch') AS date, 
     (SUM(CASE WHEN event = 'movement end' THEN timestamp END) - 
     SUM(CASE WHEN event = 'movement start' THEN timestamp END) 
     ) AS all_movement, 
     (SUM(CASE WHEN event = 'load end' THEN timestamp END) - 
     SUM(CASE WHEN event = 'load start' THEN timestamp END) 
     ) AS all_load, 
     (SUM(CASE WHEN event = 'movement end' AND 
         (SELECT event 
         FROM Table1 b 
         WHERE timestamp = (SELECT MIN(timestamp) 
              FROM Table1 c 
              WHERE c.timestamp >= a.timestamp 
              AND c.id = a.id 
              AND c.event LIKE 'load %') 
         AND b.id = a.id 
         AND b.event LIKE 'load %' 
        ) = 'load end' 
      THEN timestamp END) - 
     SUM(CASE WHEN event = 'movement start' AND 
         (SELECT event 
         FROM Table1 b 
         WHERE timestamp = (SELECT MAX(timestamp) 
              FROM Table1 c 
              WHERE c.timestamp <= a.timestamp 
              AND c.id = a.id 
              AND c.event LIKE 'load %') 
         AND b.id = a.id 
         AND b.event LIKE 'load %' 
        ) = 'load start' 
      THEN timestamp END) 
     ) AS load_movement 
FROM Table1 a 
GROUP BY id, 
     date(timestamp, 'unixepoch') 

Answer 2

问题是您开始的查询。我根本不明白第三栏是什么。但是，前两个是多使用更容易地计算出：

select (sum(case when event = 'movement end' then timestamp end) - 
     sum(case when event = 'movement start' then timestamp end) 
     ), 
     (sum(case when event = 'load end' then timestamp end) - 
     sum(case when event = 'load start' then timestamp end) 
     ) 
from table1 

由此看来，它应该是微不足道通过添加的组：

select id, date(timestamp), 
     (sum(case when event = 'movement end' then timestamp end) - 
     sum(case when event = 'movement start' then timestamp end) 
     ), 
     (sum(case when event = 'load end' then timestamp end) - 
     sum(case when event = 'load start' then timestamp end) 
     ) 
from table1 
group by id, date(timestamp)