如何合并来自同一表的两个SQL查询

Question

我在表中有以下（示例）数据

值，日期，设备

我使用数据进行简单的SLA计算，即在工作时间内多少次数据低于某个阈值。

目前，我运行以下两个查询，如下所示

select count(*), DATE(times) from SLA where device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' and value <150 group by DATE(times);

select count(*), DATE(times) from SLA where device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' group by DATE(times);

因此，有两个查询，一个查询没有值<数字，一个查询没有值。

有几个问题，是否有办法将它们全部合并到一个查询中，所以我可以看到总数据点和小于阈值的数据点的计数？ 基本上返回三列，一列带有计数，一列带有低于阈值的计数和日期

除此之外，有没有一种简单的方法可以告诉mysql在返回数据时忽略周末？

谢谢，

Answer 1

使用UNION运算符。

更新后的查询将如下所示：

(select count(*), DATE(times) from SLA where device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' and value <150 group by DATE(times))
UNION
(select count(*), DATE(times) from SLA where device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' group by DATE(times));

Answer 2

如您所写，如果需要三列 （两个计数和一个日期），请使用subselect而不是union：

select 
(select count(*) from SLA where device='some-dev' and DATE(times) = DATE(s.times) and  TIME(times) between '06:00:00' and '18:00:00' and value <150),
count(*), 
DATE(s.times) 
from SLA s
where device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' group by DATE(times)

我没有测试上面的查询，因此可能需要进行一些调整，但是请参见一个简化的工作示例 。

编辑：刚刚用一个（甚至）更有意义的查询更新了链接的小提琴（一次）。

Answer 3

select count(*), DATE(time) from SLA where (device='some-dev' and DATE(time) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' and value <150 group by DATE(time)) or (device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(time) between '06:00:00' and '18:00:00' group by DATE(time));

Answer 4

怎么样：

select count(*), DATE(times) from SLA 
where (device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' and value <150 group by DATE(times))
or (device='some-dev' and DATE(times) between '2013-05-01' and '2013-05-31' and TIME(times) between '06:00:00' and '18:00:00' group by DATE(times));

Answer 5

我使用的是ms-sql，但大概可以执行以下操作：

select count(*), DATE(times), SUM(CASE WHEN value <150  THEN 1 ELSE 0 END)
from SLA
where device='some-dev'
and DATE(times) between '2013-05-01' and '2013-05-31'
and TIME(times) between '06:00:00' and '18:00:00'
group by DATE(times);

在mysql中。