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Grouping into interval of 5 minutes within a time range

开发者 https://www.devze.com 2023-01-28 11:01 出处:网络
I have some difficulties with mySQL com开发者_如何学JAVAmands that I want to do. SELECT a.timestamp, name, count(b.name)

I have some difficulties with mySQL com开发者_如何学JAVAmands that I want to do.

SELECT a.timestamp, name, count(b.name) 
FROM time a, id b 
WHERE a.user = b.user
  AND a.id = b.id
  AND b.name = 'John'
  AND a.timestamp BETWEEN '2010-11-16 10:30:00' AND '2010-11-16 11:00:00' 
GROUP BY a.timestamp

This is my current output statement.

timestamp            name  count(b.name)
-------------------  ----  -------------
2010-11-16 10:32:22  John  2
2010-11-16 10:35:12  John  7
2010-11-16 10:36:34  John  1
2010-11-16 10:37:45  John  2
2010-11-16 10:48:26  John  8
2010-11-16 10:55:00  John  9
2010-11-16 10:58:08  John  2

How do I group them into 5 minutes interval results?

I want my output to be like

timestamp            name  count(b.name)
-------------------  ----  -------------
2010-11-16 10:30:00  John  2
2010-11-16 10:35:00  John  10
2010-11-16 10:40:00  John  0
2010-11-16 10:45:00  John  8
2010-11-16 10:50:00  John  0
2010-11-16 10:55:00  John  11 


This works with every interval.

PostgreSQL

SELECT
    TIMESTAMP WITH TIME ZONE 'epoch' +
    INTERVAL '1 second' * round(extract('epoch' from timestamp) / 300) * 300 as timestamp,
    name,
    count(b.name)
FROM time a, id 
WHERE …
GROUP BY 
round(extract('epoch' from timestamp) / 300), name


MySQL

SELECT
    timestamp,  -- not sure about that
    name,
    count(b.name)
FROM time a, id 
WHERE …
GROUP BY 
UNIX_TIMESTAMP(timestamp) DIV 300, name


I came across the same issue.

I found that it is easy to group by any minute interval is just dividing epoch by minutes in amount of seconds and then either rounding or using floor to get ride of the remainder. So if you want to get interval in 5 minutes you would use 300 seconds.

    SELECT COUNT(*) cnt, 
    to_timestamp(floor((extract('epoch' from timestamp_column) / 300 )) * 300) 
    AT TIME ZONE 'UTC' as interval_alias
    FROM TABLE_NAME GROUP BY interval_alias
interval_alias       cnt
-------------------  ----  
2010-11-16 10:30:00  2
2010-11-16 10:35:00  10
2010-11-16 10:45:00  8
2010-11-16 10:55:00  11 

This will return the data correctly group by the selected minutes interval; however, it will not return the intervals that don't contains any data. In order to get those empty intervals we can use the function generate_series.

    SELECT generate_series(MIN(date_trunc('hour',timestamp_column)),
    max(date_trunc('minute',timestamp_column)),'5m') as interval_alias FROM 
    TABLE_NAME

Result:

interval_alias       
-------------------    
2010-11-16 10:30:00  
2010-11-16 10:35:00
2010-11-16 10:40:00   
2010-11-16 10:45:00
2010-11-16 10:50:00   
2010-11-16 10:55:00   

Now to get the result with interval with zero occurrences we just outer join both result sets.

    SELECT series.minute as interval,  coalesce(cnt.amnt,0) as count from 
       (
       SELECT count(*) amnt,
       to_timestamp(floor((extract('epoch' from timestamp_column) / 300 )) * 300)
       AT TIME ZONE 'UTC' as interval_alias
       from TABLE_NAME  group by interval_alias
       ) cnt
    
    RIGHT JOIN 
       (    
       SELECT generate_series(min(date_trunc('hour',timestamp_column)),
       max(date_trunc('minute',timestamp_column)),'5m') as minute from TABLE_NAME 
       ) series
  on series.minute = cnt.interval_alias

The end result will include the series with all 5 minute intervals even those that have no values.

interval             count
-------------------  ----  
2010-11-16 10:30:00  2
2010-11-16 10:35:00  10
2010-11-16 10:40:00  0
2010-11-16 10:45:00  8
2010-11-16 10:50:00  0 
2010-11-16 10:55:00  11 

The interval can be easily changed by adjusting the last parameter of generate_series. In our case we use '5m' but it could be any interval we want.


You should rather use GROUP BY UNIX_TIMESTAMP(time_stamp) DIV 300 instead of round(../300) because of the rounding I found that some records are counted into two grouped result sets.


For postgres, I found it easier and more accurate to use the

date_trunc

function, like:

select name, sum(count), date_trunc('minute',timestamp) as timestamp
FROM table
WHERE xxx
GROUP BY name,date_trunc('minute',timestamp)
ORDER BY timestamp

You can provide various resolutions like 'minute','hour','day' etc... to date_trunc.


The query will be something like:

SELECT 
  DATE_FORMAT(
    MIN(timestamp),
    '%d/%m/%Y %H:%i:00'
  ) AS tmstamp,
  name,
  COUNT(id) AS cnt 
FROM
  table
GROUP BY ROUND(UNIX_TIMESTAMP(timestamp) / 300), name


Not sure if you still need it.

SELECT FROM_UNIXTIME(FLOOR((UNIX_TIMESTAMP(timestamp))/300)*300) AS t,timestamp,count(1) as c from users GROUP BY t ORDER BY t;

2016-10-29 19:35:00 | 2016-10-29 19:35:50 | 4 |

2016-10-29 19:40:00 | 2016-10-29 19:40:37 | 5 |

2016-10-29 19:45:00 | 2016-10-29 19:45:09 | 6 |

2016-10-29 19:50:00 | 2016-10-29 19:51:14 | 4 |

2016-10-29 19:55:00 | 2016-10-29 19:56:17 | 1 |


You're probably going to have to break up your timestamp into ymd:HM and use DIV 5 to split the minutes up into 5-minute bins -- something like

select year(a.timestamp), 
       month(a.timestamp), 
       hour(a.timestamp), 
       minute(a.timestamp) DIV 5,
       name, 
       count(b.name)
FROM time a, id b
WHERE a.user = b.user AND a.id = b.id AND b.name = 'John' 
      AND a.timestamp BETWEEN '2010-11-16 10:30:00' AND '2010-11-16 11:00:00'
GROUP BY year(a.timestamp), 
       month(a.timestamp), 
       hour(a.timestamp), 
       minute(a.timestamp) DIV 12

...and then futz the output in client code to appear the way you like it. Or, you can build up the whole date string using the sql concat operatorinstead of getting separate columns, if you like.

select concat(year(a.timestamp), "-", month(a.timestamp), "-" ,day(a.timestamp), 
       " " , lpad(hour(a.timestamp),2,'0'), ":", 
       lpad((minute(a.timestamp) DIV 5) * 5, 2, '0'))

...and then group on that


How about this one:

select 
    from_unixtime(unix_timestamp(timestamp) - unix_timestamp(timestamp) mod 300) as ts,  
    sum(value)
from group_interval 
group by ts 
order by ts
;


I found out that with MySQL probably the correct query is the following:

SELECT SUBSTRING( FROM_UNIXTIME( CEILING( timestamp /300 ) *300,  
                                 '%Y-%m-%d %H:%i:%S' ) , 1, 19 ) AS ts_CEILING,
SUM(value)
FROM group_interval
GROUP BY SUBSTRING( FROM_UNIXTIME( CEILING( timestamp /300 ) *300,  
                                   '%Y-%m-%d %H:%i:%S' ) , 1, 19 )
ORDER BY SUBSTRING( FROM_UNIXTIME( CEILING( timestamp /300 ) *300,  
                                   '%Y-%m-%d %H:%i:%S' ) , 1, 19 ) DESC

Let me know what you think.


select 
CONCAT(CAST(CREATEDATE AS DATE),' ',datepart(hour,createdate),':',ROUNd(CAST((CAST((CAST(DATEPART(MINUTE,CREATEDATE) AS DECIMAL (18,4)))/5 AS INT)) AS DECIMAL (18,4))/12*60,2)) AS '5MINDATE'
,count(something)
from TABLE
group by CONCAT(CAST(CREATEDATE AS DATE),' ',datepart(hour,createdate),':',ROUNd(CAST((CAST((CAST(DATEPART(MINUTE,CREATEDATE) AS DECIMAL (18,4)))/5 AS INT)) AS DECIMAL (18,4))/12*60,2))


This will do exactly what you want.

Replace

  • dt - your datetime
  • c - call field
  • astro_transit1 - your table
  • 300 as seconds for each time gap increase
SELECT 
    FROM_UNIXTIME(300 * ROUND(UNIX_TIMESTAMP(r.dt) / 300)) AS 5datetime,
    (SELECT 
            r.c
        FROM
            astro_transit1 ra
        WHERE
            ra.dt = r.dt
        ORDER BY ra.dt DESC
        LIMIT 1) AS first_val
FROM
    astro_transit1 r
GROUP BY UNIX_TIMESTAMP(r.dt) DIV 300
LIMIT 0 , 30


Based on @boecko answer for MySQL, I used a CTE (Common Table Expression) to accelerate the query execution time :

so this :

SELECT
    `timestamp`,
    `name`,
     count(b.`name`)
FROM `time` a, `id` b
WHERE …
GROUP BY 
UNIX_TIMESTAMP(`timestamp`) DIV 300, name  

becomes :

WITH cte AS (
    SELECT
        `timestamp`,
        `name`,
         count(b.`name`),
         UNIX_TIMESTAMP(`timestamp`) DIV 300 AS `intervals`
    FROM `time` a, `id` b
    WHERE …
)
SELECT * FROM cte GROUP BY `intervals`

In a large amount of data, the speed is accelerated by more than 10!

As timestamp and time are reserved in MySQL, don't forget to use `...` on each table and column name !

Hope it will help some of you.

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