MySql查询组按天和按时间
我想创建一个SQL查询来解决我的问题。
MySql查询组按天和按时间
我的表:
+----+---------------------+-------+
| id | date | value |
+----+---------------------+-------+
| 1 | 2014-10-10 05:10:10 | 10 |
+----+---------------------+-------+
| 2 | 2014-10-10 09:10:10 | 20 |
+----+---------------------+-------+
| 3 | 2014-10-10 15:10:10 | 30 |
+----+---------------------+-------+
| 4 | 2014-10-10 23:10:10 | 40 |
+----+---------------------+-------+
| 5 | 2014-10-11 08:10:10 | 15 |
+----+---------------------+-------+
| 6 | 2014-10-11 09:10:10 | 25 |
+----+---------------------+-------+
| 7 | 2014-10-11 10:10:10 | 30 |
+----+---------------------+-------+
| 8 | 2014-10-11 23:10:10 | 40 |
+----+---------------------+-------+
我想天总结在组值,这天三个亚组类似“早晨”(06:00 - 12:00),“午”( 12:00 - 18:00)和'晚上'(00:00 - 06:00和18:00 - 24:00)。
是这样的:
+------------+-------+---------+-----------+-------+
| date | value | morning | afternoon | night |
+------------+-------+---------+-----------+-------+
| 2014-10-10 | 100 | 20 | 30 | 50 |
+------------+-------+---------+-----------+-------+
| 2014-10-11 | 110 | 70 | 0 | 40 |
+------------+-------+---------+-----------+-------+
你可以用一对夫妇的sum
结束了case
表达式:
SELECT DAY(`date`) AS `date`
SUM(CASE WHEN HOUR(`date`) BETWEEN 6 AND 12 THEN value ELSE 0 END) AS `morning`,
SUM(CASE WHEN HOUR(`date`) BETWEEN 12 AND 18 THEN value ELSE 0 END) AS `afternoon`,
SUM(CASE WHEN HOUR(`date`) < 6 OR HOUR(`date`) > 18 THEN value ELSE 0 END) AS `evening`
FROM my_table
GROUP BY DAY(`date`)
有多种方法去了解这一点,但我自己我会做通过首先提取CROSS APPLY中的伪信息,然后将该信息分组。
我相信这提供了重要的可读性好处,并允许您在其他子句中重新使用任何计算。例如,你已经集中了分组机制,这意味着你只需要在一个地方而不是在select和group by中进行更改。同样,您可以将“extraData.Morning = 1”添加到WHERE子句中,而不是重新编写早上的计算。
例如:
CREATE TABLE #TestData (ID INT, Data DATETIME, Value INT)
INSERT INTO #TestData (ID, Data, Value) VALUES
(1 ,'2014-10-10 05:10:10' ,10)
,(2 ,'2014-10-10 09:10:10' ,20)
,(3 ,'2014-10-10 15:10:10' ,30)
,(4 ,'2014-10-10 23:10:10' ,40)
,(5 ,'2014-10-11 08:10:10' ,15)
,(6 ,'2014-10-11 09:10:10' ,25)
,(7 ,'2014-10-11 10:10:10' ,30)
,(8 ,'2014-10-11 23:10:10' ,40)
SELECT
extraData.DayComponent
,SUM(td.Value)
,SUM(CASE WHEN extraData.Morning = 1 THEN td.Value ELSE 0 END) AS Morning
,SUM(CASE WHEN extraData.Afternoon = 1 THEN td.Value ELSE 0 END) AS Afternoon
,SUM(CASE WHEN extraData.Night = 1 THEN td.Value ELSE 0 END) AS Night
FROM #TestData td
CROSS APPLY (
SELECT
DATEADD(dd, 0, DATEDIFF(dd, 0, td.Data)) AS DayComponent
,CASE WHEN DATEPART(HOUR, td.Data) BETWEEN 6 AND 12 THEN 1 ELSE 0 END AS Morning
,CASE WHEN DATEPART(HOUR, td.Data) BETWEEN 12 AND 18 THEN 1 ELSE 0 END AS Afternoon
,CASE WHEN DATEPART(HOUR, td.Data) BETWEEN 0 AND 6
OR DATEPART(HOUR, td.Data) BETWEEN 18 AND 24 THEN 1 ELSE 0 END AS Night
) extraData
GROUP BY
extraData.DayComponent
DROP TABLE #TestData
交叉应用是SQL Server的唯一不是吗? – 2014-10-10 16:43:46
啊,我的道歉,没有注意到mySQL标签。应该采取表格格式的提示。 – mrmillsy 2014-10-11 00:21:00
非常感谢您!它工作得很好。 – 2014-10-10 17:17:28