Grupo MySQL por horas
Estoy tratando de obtener un informe de mi tabla de historial por uso por hora. history la mesa es;
CREATE TABLE IF NOT EXISTS `history` (
`history_id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`user_id` int(11) unsigned NOT NULL DEFAULT '0',
`created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`history_id`),
KEY `user_id` (`user_id`),
KEY `created` (`created`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;
Quiero agrupar por HOUR y COUNT todos los registros en un intervalo de fechas determinado.
Hours | Usage
------------------------------------
00:00-01:00 | 5
01:00-02:00 | 9
02:00-03:00 | 0 (or NULL)
03:00-04:00 | 20
...
...
...
22:00-23:00 | 11
23:00-00:00 | 1
Utilicé una consulta como esta, pero no muestra todas las horas.
SELECT
CASE
WHEN HOUR(created) BETWEEN 0 AND 1 THEN '00:00 - 01:00'
WHEN HOUR(created) BETWEEN 1 AND 2 THEN '01:00 - 02:00'
WHEN HOUR(created) BETWEEN 2 AND 3 THEN '02:00 - 03:00'
WHEN HOUR(created) BETWEEN 3 AND 4 THEN '03:00 - 04:00'
WHEN HOUR(created) BETWEEN 4 AND 5 THEN '04:00 - 05:00'
WHEN HOUR(created) BETWEEN 5 AND 6 THEN '05:00 - 06:00'
WHEN HOUR(created) BETWEEN 6 AND 7 THEN '06:00 - 07:00'
WHEN HOUR(created) BETWEEN 7 AND 8 THEN '07:00 - 08:00'
WHEN HOUR(created) BETWEEN 8 AND 9 THEN '08:00 - 09:00'
WHEN HOUR(created) BETWEEN 9 AND 10 THEN '09:00 - 10:00'
WHEN HOUR(created) BETWEEN 10 AND 11 THEN '10:00 - 11:00'
WHEN HOUR(created) BETWEEN 11 AND 12 THEN '11:00 - 12:00'
WHEN HOUR(created) BETWEEN 12 AND 13 THEN '12:00 - 13:00'
WHEN HOUR(created) BETWEEN 13 AND 14 THEN '13:00 - 14:00'
WHEN HOUR(created) BETWEEN 14 AND 15 THEN '14:00 - 15:00'
WHEN HOUR(created) BETWEEN 15 AND 16 THEN '15:00 - 16:00'
WHEN HOUR(created) BETWEEN 16 AND 17 THEN '16:00 - 17:00'
WHEN HOUR(created) BETWEEN 17 AND 18 THEN '17:00 - 18:00'
WHEN HOUR(created) BETWEEN 18 AND 19 THEN '18:00 - 19:00'
WHEN HOUR(created) BETWEEN 19 AND 20 THEN '19:00 - 20:00'
WHEN HOUR(created) BETWEEN 20 AND 21 THEN '20:00 - 21:00'
WHEN HOUR(created) BETWEEN 21 AND 22 THEN '21:00 - 23:00'
WHEN HOUR(created) BETWEEN 22 AND 23 THEN '22:00 - 23:00'
WHEN HOUR(created) BETWEEN 23 AND 24 THEN '23:00 - 00:00'
END AS `Hours`,
COUNT(*) AS `usage`
FROM history
WHERE (created BETWEEN '2012-02-07' AND NOW())
GROUP BY
CASE
WHEN HOUR(created) BETWEEN 0 AND 1 THEN 1
WHEN HOUR(created) BETWEEN 1 AND 2 THEN 2
WHEN HOUR(created) BETWEEN 2 AND 3 THEN 3
WHEN HOUR(created) BETWEEN 3 AND 4 THEN 4
WHEN HOUR(created) BETWEEN 4 AND 5 THEN 5
WHEN HOUR(created) BETWEEN 5 AND 6 THEN 6
WHEN HOUR(created) BETWEEN 6 AND 7 THEN 7
WHEN HOUR(created) BETWEEN 7 AND 8 THEN 8
WHEN HOUR(created) BETWEEN 8 AND 9 THEN 9
WHEN HOUR(created) BETWEEN 9 AND 10 THEN 10
WHEN HOUR(created) BETWEEN 10 AND 11 THEN 11
WHEN HOUR(created) BETWEEN 11 AND 12 THEN 12
WHEN HOUR(created) BETWEEN 12 AND 13 THEN 13
WHEN HOUR(created) BETWEEN 13 AND 14 THEN 14
WHEN HOUR(created) BETWEEN 14 AND 15 THEN 15
WHEN HOUR(created) BETWEEN 15 AND 16 THEN 16
WHEN HOUR(created) BETWEEN 16 AND 17 THEN 17
WHEN HOUR(created) BETWEEN 17 AND 18 THEN 18
WHEN HOUR(created) BETWEEN 18 AND 19 THEN 19
WHEN HOUR(created) BETWEEN 19 AND 20 THEN 20
WHEN HOUR(created) BETWEEN 20 AND 21 THEN 21
WHEN HOUR(created) BETWEEN 21 AND 22 THEN 22
WHEN HOUR(created) BETWEEN 22 AND 23 THEN 23
WHEN HOUR(created) BETWEEN 23 AND 24 THEN 24
END
Solo se muestra si hay registros.
Hours | Usage
------------------------------------
00:00-01:00 | 5
01:00-02:00 | 9
23:00-00:00 | 1
preguntado el 03 de mayo de 12 a las 11:05
Burak Erdem
4 Respuestas
Su consulta existente se puede reducir a:
SELECT CONCAT(HOUR(created), ':00-', HOUR(created)+1, ':00') AS Hours
, COUNT(*) AS `usage`
FROM history
WHERE created BETWEEN '2012-02-07' AND NOW()
GROUP BY HOUR(created)
Para mostrar cada hora, incluidas aquellas para las que no hay datos, debe realizar una combinación externa con una tabla que contenga todas las horas para las que desea datos. Puede construir una tabla de este tipo en su consulta usando UNION:
SELECT CONCAT(Hour, ':00-', Hour+1, ':00') AS Hours
, COUNT(created) AS `usage`
FROM history
RIGHT JOIN (
SELECT 0 AS Hour
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12
UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15
UNION ALL SELECT 16 UNION ALL SELECT 17 UNION ALL SELECT 18
UNION ALL SELECT 19 UNION ALL SELECT 20 UNION ALL SELECT 21
UNION ALL SELECT 22 UNION ALL SELECT 23
) AS AllHours ON HOUR(created) = Hour
WHERE created BETWEEN '2012-02-07' AND NOW() OR created IS NULL
GROUP BY Hour
ORDER BY Hour
Sin embargo, el tratamiento de grupos para los que no existen datos es realmente una cuestión de lógica comercial que está mejor ubicada en su capa de acceso a datos en lugar de en la base de datos misma: de hecho, debería ser trivial para su aplicación usar un valor cero cada vez que una hora es ausente.
Respondido el 19 de Septiembre de 15 a las 12:09
Dada una mesa Log con columnas ts y propuesta de, lo siguiente dará el promedio por hora de las últimas 24 horas (suponiendo que cada hora tenga al menos una fila).
SELECT
FROM_UNIXTIME( TRUNCATE( UNIX_TIMESTAMP( `ts` )/3600, 0 ) * 3600 ) as h,
AVG( `value` ) as v,
COUNT( * ) as q
FROM
Log
GROUP BY
h
ORDER BY
h desc
LIMIT
24
La columna ts puede ser una columna de marca de tiempo o fecha y hora mientras propuesta de es cualquier cosa que AVG() aceptará.
Respondido el 06 de enero de 16 a las 10:01
Modificando la respuesta de @eggyal, ya que otro buen caso de uso sería mostrar el día junto con las horas.
Suponga que necesita COUNT de registros de los últimos 7 días, que es de 24 horas cada uno.
SELECT
dayname(date_sub(curdate(), INTERVAL 1 DAY)) AS Day,
CONCAT(Hour, ':00-', Hour+1, ':00') AS Hour,
COUNT(created) AS `usage`
FROM
history
RIGHT JOIN
(
SELECT 0 AS Hour
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12
UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15
UNION ALL SELECT 16 UNION ALL SELECT 17 UNION ALL SELECT 18
UNION ALL SELECT 19 UNION ALL SELECT 20 UNION ALL SELECT 21
UNION ALL SELECT 22 UNION ALL SELECT 23
)
AS totalhours
ON HOUR(created) = HOUR
AND DATE(created) = date_sub(curdate(), INTERVAL 1 DAY)
OR created IS NULL
GROUP BY
Hour
ORDER BY
Hour;
Modificando esto en la lógica de negocios del código backend o en un procedimiento almacenado,
INTERVAL 1 DAY
puede generar resultados de consultas de los últimos 7 días junto con el nombre del día.
Respondido el 29 de Septiembre de 20 a las 13:09
Sobre la base de la respuesta de Prashanth, recibí una advertencia sobre la ambigüedad de Hour (Percona 5.7). Además, no estaba obteniendo los resultados en el orden correcto. Lo siguiente resolvió estos problemas para mí y es más claro con respecto a las cláusulas GROUP BY y ORDER BY:
SELECT
dayname(date_sub(curdate(), INTERVAL 1 DAY)) AS Day,
CONCAT(Hour, ':00-', Hour+1, ':00') AS Hour,
COUNT(created_at) AS `total`
FROM logtable
RIGHT JOIN
(
SELECT 0 AS Hour
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12
UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15
UNION ALL SELECT 16 UNION ALL SELECT 17 UNION ALL SELECT 18
UNION ALL SELECT 19 UNION ALL SELECT 20 UNION ALL SELECT 21
UNION ALL SELECT 22 UNION ALL SELECT 23
)
AS totalhours
ON ( HOUR(created_at) = HOUR
AND DATE(created_at) = date_sub(curdate(), INTERVAL 1 DAY) )
OR created_at IS NULL
GROUP BY
CONCAT(Hour, ':00-', Hour+1, ':00')
ORDER BY
totalhours.Hour;
Respondido el 30 de junio de 21 a las 22:06
No es la respuesta que estás buscando? Examinar otras preguntas etiquetadas mysql sql group-by or haz tu propia pregunta.
Cree una tabla temporal con todas las horas y únase a la izquierda con sus datos reales. - Jeroen Bolle