值在范围内时的mysql分组

coder 2023-10-17 原文

我到处搜索，似乎找不到任何关于如何处理我的查询的信息。如果我问的是一个愚蠢的问题，我提前道歉，但我真的需要一些帮助。

我有一系列以不同时间间隔记录的值。数据如下所示:

 timeStamp           | RPM 
 2012-05-01 01:02:56 | 802
 2012-05-01 01:03:45 | 845
 2012-05-01 01:04:50 | 825
 2012-05-01 01:05:55 | 810
 2012-05-01 01:07:00 | 1000
 2012-05-01 01:08:03 | 1005
 2012-05-01 01:09:05 | 1145
 2012-05-01 01:10:15 | 1110
 2012-05-01 01:11:20 | 800
 2012-05-01 01:12:22 | 812
 2012-05-01 01:13:20 | 820
 2012-05-01 01:14:20 | 820
 2012-05-01 01:15:20 | 1200

示例中的 RPM 是发动机 RPM。

当 RPM 在 800-900 范围内时，我需要开始和结束时间戳，因为这被视为引擎空转。我还希望能够返回每个非空闲时间段的开始和结束时间。

我想要得到的结果是这样的:

Period    | startTime           | endTime             | duration 
 Idle1    | 2012-05-01 01:02:56 | 2012-05-01 01:05:55 | 179 seconds 
 nonIdle1 | 2012-05-01 01:07:00 | 2012-05-01 01:10:15 | 195 seconds 
 idle2    | 2012-05-01 01:11:20 | 2012-05-01 01:14:20 | 180 seconds

在此先感谢您的帮助。

谢谢

最佳答案

试试这个:http://www.sqlfiddle.com/#!2/e9372/1

在数据库端这样做的好处是您不仅可以在 PHP 上使用查询，还可以在 Java、C#、Python 等上使用它。而且在数据库端这样做速度很快

select 
  if(idle_state = 1, 
       concat('Idle ', idle_count), 
       concat('NonIdle ', non_idle_count) ) as Period,
  startTime, endTime, duration
from
(

  select 

    @idle_count := @idle_count + if(idle_state = 1,1,0) as idle_count,
    @non_idle_count := @non_idle_count +if(idle_state = 0,1,0) as non_idle_count,

    state_group, idle_state,
    min(timeStamp) as startTime, max(timeStamp) as endTime,
    timestampdiff(second, min(timeStamp), max(timeStamp)) as duration
  from
  (
    select *,        
      @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
      @state_group := @state_group + 
                      if(@idle_state = @prev_state,0,1) as state_group,
      @prev_state := @idle_state
    from (tbl, (select @state_group := 0 as y) as vars)
    order by tbl.timeStamp
  ) as x
  ,(select @idle_count := 0 as y, @non_idle_count := 0 as z) as vars
  group by state_group, idle_state

) as summary

输出:

|    PERIOD |                  STARTTIME |                    ENDTIME | DURATION |
|-----------|----------------------------|----------------------------|----------|
|    Idle 1 | May, 01 2012 01:02:56-0700 | May, 01 2012 01:05:55-0700 |      179 |
| NonIdle 1 | May, 01 2012 01:07:00-0700 | May, 01 2012 01:10:15-0700 |      195 |
|    Idle 2 | May, 01 2012 01:11:20-0700 | May, 01 2012 01:14:20-0700 |      180 |
| NonIdle 2 | May, 01 2012 01:15:20-0700 | May, 01 2012 01:15:20-0700 |        0 |

在此处查看查询进度:http://www.sqlfiddle.com/#!2/e9372/1

工作原理:

五个步骤。

首先，将空闲与非空闲分开:

select *,
  @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state
from (tbl, (select @state_group := 0 as y) as vars)
order by tbl.timeStamp;

输出:

|                  TIMESTAMP |  RPM | Y | IDLE_STATE |
|----------------------------|------|---|------------|
| May, 01 2012 01:02:56-0700 |  802 | 0 |          1 |
| May, 01 2012 01:03:45-0700 |  845 | 0 |          1 |
| May, 01 2012 01:04:50-0700 |  825 | 0 |          1 |
| May, 01 2012 01:05:55-0700 |  810 | 0 |          1 |
| May, 01 2012 01:07:00-0700 | 1000 | 0 |          0 |
| May, 01 2012 01:08:03-0700 | 1005 | 0 |          0 |
| May, 01 2012 01:09:05-0700 | 1145 | 0 |          0 |
| May, 01 2012 01:10:15-0700 | 1110 | 0 |          0 |
| May, 01 2012 01:11:20-0700 |  800 | 0 |          1 |
| May, 01 2012 01:12:22-0700 |  812 | 0 |          1 |
| May, 01 2012 01:13:20-0700 |  820 | 0 |          1 |
| May, 01 2012 01:14:20-0700 |  820 | 0 |          1 |
| May, 01 2012 01:15:20-0700 | 1200 | 0 |          0 |

其次，将更改分成几组:

select *,  
  @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
  @state_group := @state_group + 
                  if(@idle_state = @prev_state,0,1) as state_group,
  @prev_state := @idle_state

from (tbl, (select @state_group := 0 as y) as vars)
order by tbl.timeStamp;

输出:

|                  TIMESTAMP |  RPM | Y | IDLE_STATE | STATE_GROUP | @PREV_STATE := @IDLE_STATE |
|----------------------------|------|---|------------|-------------|----------------------------|
| May, 01 2012 01:02:56-0700 |  802 | 0 |          1 |           1 |                          1 |
| May, 01 2012 01:03:45-0700 |  845 | 0 |          1 |           1 |                          1 |
| May, 01 2012 01:04:50-0700 |  825 | 0 |          1 |           1 |                          1 |
| May, 01 2012 01:05:55-0700 |  810 | 0 |          1 |           1 |                          1 |
| May, 01 2012 01:07:00-0700 | 1000 | 0 |          0 |           2 |                          0 |
| May, 01 2012 01:08:03-0700 | 1005 | 0 |          0 |           2 |                          0 |
| May, 01 2012 01:09:05-0700 | 1145 | 0 |          0 |           2 |                          0 |
| May, 01 2012 01:10:15-0700 | 1110 | 0 |          0 |           2 |                          0 |
| May, 01 2012 01:11:20-0700 |  800 | 0 |          1 |           3 |                          1 |
| May, 01 2012 01:12:22-0700 |  812 | 0 |          1 |           3 |                          1 |
| May, 01 2012 01:13:20-0700 |  820 | 0 |          1 |           3 |                          1 |
| May, 01 2012 01:14:20-0700 |  820 | 0 |          1 |           3 |                          1 |
| May, 01 2012 01:15:20-0700 | 1200 | 0 |          0 |           4 |                          0 |

第三，将它们分组，并计算持续时间:

select 
  state_group, idle_state,
  min(timeStamp) as startTime, max(timeStamp) as endTime,
  timestampdiff(second, min(timeStamp), max(timeStamp)) as duration
from
(
  select *,    
    @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
    @state_group := @state_group + 
                    if(@idle_state = @prev_state,0,1) as state_group,
    @prev_state := @idle_state
  from (tbl, (select @state_group := 0 as y) as vars)
  order by tbl.timeStamp
) as x
group by state_group, idle_state;

输出:

| STATE_GROUP | IDLE_STATE |                  STARTTIME |                    ENDTIME | DURATION |
|-------------|------------|----------------------------|----------------------------|----------|
|           1 |          1 | May, 01 2012 01:02:56-0700 | May, 01 2012 01:05:55-0700 |      179 |
|           2 |          0 | May, 01 2012 01:07:00-0700 | May, 01 2012 01:10:15-0700 |      195 |
|           3 |          1 | May, 01 2012 01:11:20-0700 | May, 01 2012 01:14:20-0700 |      180 |
|           4 |          0 | May, 01 2012 01:15:20-0700 | May, 01 2012 01:15:20-0700 |        0 |

第四，获取空闲和非空闲计数:

select 

  @idle_count := @idle_count + if(idle_state = 1,1,0) as idle_count,
  @non_idle_count := @non_idle_count + if(idle_state = 0,1,0) as non_idle_count,

  state_group, idle_state,
  min(timeStamp) as startTime, max(timeStamp) as endTime,
  timestampdiff(second, min(timeStamp), max(timeStamp)) as duration
from
(
  select *,        
    @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
    @state_group := @state_group + 
                    if(@idle_state = @prev_state,0,1) as state_group,
    @prev_state := @idle_state
  from (tbl, (select @state_group := 0 as y) as vars)
  order by tbl.timeStamp
) as x
,(select @idle_count := 0 as y, @non_idle_count := 0 as z) as vars
group by state_group, idle_state;

输出:

| IDLE_COUNT | NON_IDLE_COUNT | STATE_GROUP | IDLE_STATE |                  STARTTIME |                    ENDTIME | DURATION |
|------------|----------------|-------------|------------|----------------------------|----------------------------|----------|
|          1 |              0 |           1 |          1 | May, 01 2012 01:02:56-0700 | May, 01 2012 01:05:55-0700 |      179 |
|          1 |              1 |           2 |          0 | May, 01 2012 01:07:00-0700 | May, 01 2012 01:10:15-0700 |      195 |
|          2 |              1 |           3 |          1 | May, 01 2012 01:11:20-0700 | May, 01 2012 01:14:20-0700 |      180 |
|          2 |              2 |           4 |          0 | May, 01 2012 01:15:20-0700 | May, 01 2012 01:15:20-0700 |        0 |

最后，删除暂存变量:

select 
  if(idle_state = 1, 
       concat('Idle ', idle_count), 
       concat('NonIdle ', non_idle_count) ) as Period,
  startTime, endTime, duration
from
(

  select 

    @idle_count := @idle_count + if(idle_state = 1,1,0) as idle_count,
    @non_idle_count := @non_idle_count +if(idle_state = 0,1,0) as non_idle_count,

    state_group, idle_state,
    min(timeStamp) as startTime, max(timeStamp) as endTime,
    timestampdiff(second, min(timeStamp), max(timeStamp)) as duration
  from
  (
    select *,        
      @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
      @state_group := @state_group + 
                      if(@idle_state = @prev_state,0,1) as state_group,
      @prev_state := @idle_state
    from (tbl, (select @state_group := 0 as y) as vars)
    order by tbl.timeStamp
  ) as x
  ,(select @idle_count := 0 as y, @non_idle_count := 0 as z) as vars
  group by state_group, idle_state

) as summary

输出:

|    PERIOD |                  STARTTIME |                    ENDTIME | DURATION |
|-----------|----------------------------|----------------------------|----------|
|    Idle 1 | May, 01 2012 01:02:56-0700 | May, 01 2012 01:05:55-0700 |      179 |
| NonIdle 1 | May, 01 2012 01:07:00-0700 | May, 01 2012 01:10:15-0700 |      195 |
|    Idle 2 | May, 01 2012 01:11:20-0700 | May, 01 2012 01:14:20-0700 |      180 |
| NonIdle 2 | May, 01 2012 01:15:20-0700 | May, 01 2012 01:15:20-0700 |        0 |

在此处查看查询进度:http://www.sqlfiddle.com/#!2/e9372/1

更新

查询可以缩短http://www.sqlfiddle.com/#!2/418cb/1

如果您注意到，周期数只是串联(idle-nonIdle、idle-nonIdle 等等)。你可以这样做:

select 


  case when idle_state then
     concat('Idle ', @rn := @rn + 1) 
  else
     concat('Non-idle ', @rn )
  end as Period,


  min(timeStamp) as startTime, max(timeStamp) as endTime,

  timestampdiff(second, min(timeStamp), max(timeStamp)) as duration

from
(
  select *,        
  @idle_state := if(rpm between 800 and 900, 1, 0) as idle_state,
  @state_group := @state_group + if(@idle_state = @prev_state,0,1) as state_group,
  @prev_state := @idle_state
  from (tbl, (select @state_group := 0 as y) as vars)
  order by tbl.timeStamp
) as x,
(select @rn := 0) as rx
group by state_group, idle_state

输出:

|     PERIOD |                  STARTTIME |                    ENDTIME | DURATION |
|------------|----------------------------|----------------------------|----------|
|     Idle 1 | May, 01 2012 01:02:56-0700 | May, 01 2012 01:05:55-0700 |      179 |
| Non-idle 1 | May, 01 2012 01:07:00-0700 | May, 01 2012 01:10:15-0700 |      195 |
|     Idle 2 | May, 01 2012 01:11:20-0700 | May, 01 2012 01:14:20-0700 |      180 |
| Non-idle 2 | May, 01 2012 01:15:20-0700 | May, 01 2012 01:15:20-0700 |        0 |

关于值在范围内时的mysql分组，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10842885/

mysql 值在 state 01 2012

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值在范围内时的mysql分组

工作原理:

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