Question

我有以下mysql表：

Start Time  End Time    Duration
17:00:02    17:00:31    00:00:29    
17:02:30    17:02:41    00:00:11    
17:11:25    17:15:25    00:04:00    
17:15:37    17:17:51    00:02:14    
17:18:08    17:20:17    00:02:09    
17:20:35    17:20:37    00:00:02    
17:20:39    17:21:25    00:00:46    
17:21:33    17:22:02    00:00:29

每当持续时间少于2分钟时，我需要合并行：这应该如下所示：

Start Time  End Time    Duration
17:00:02    17:15:25    00:04:40    
17:15:37    17:17:51    00:02:14    
17:18:08    17:20:17    00:02:09    
17:20:35    17:22:02    00:01:17

怎么可以这样做？您可以假设开始时间/结束时间/持续时间已经在unix时间戳中。

Answer 1

您可以通过为每个行分配一个组然后按组进行聚合来完成此操作。在这种情况下，该组是数据中较早出现持续时间超过2分钟的记录的次数：

select min(StartTime) as StartTime, max(EndTime) as EndTime, sum(Duration) as Duration
from (select t.*,
             (select count(*)
              from table t2
              where t2.StartTime < t.StartTime and
                    t2.Duration >= '00:02:00'
             ) as grp
      from table t
     ) t
group by grp;

Answer 2

这在PHP中可能比MySQL更有效：

$results = array();
$curstart = null;
while ($row = $stmt->fetch_assoc()) {
    if ($curstart == null) {
        $curstart = $row['start_time'];
        $curdur = 0;
    }
    $curdur += $row['duration'];
    $curend = $row['end_time']
    if ($row['duration'] >= 120) {
        $results[] = array('start_time' => $curstart, 
                           'end_time' => $end_time,
                           'duration' => $curdur);
        $curstart = null;
        $curdur = 0;
    }
}
if ($curstart != null) { // Get last block if it didn't end with duration > 2 min
    $results[] = array('start_time' => $curstart, 
                       'end_time' => $end_time,
                       'duration' => $curdur);
}

Answer 3

经过一番努力，这里是：

select min(start_time) start_time, max(end_time) end_time, 
  TIME_FORMAT(SEC_TO_TIME(sum(duration)),'%i:%s') duration
from (
  select start_time, end_time, duration, 
    if (@dur>=120, @grp:=@grp+1, @grp) g,
    if (@dur>=120, @dur:=duration, @dur:=@dur+duration) dur
  from mytable a
  join (select @dur:=0, @grp:=0) b) a
group by a.g;

demo

MySQL根据间隔加入多行

3 个答案: