我正在使用以下在网上找到的MySQL来生成日期列表。 但是,我希望它按分钟生成date_times列表,例如yyyy-mm-dd hh:mm:ss。 这可能吗?我无法确定现有SQL是如何生成列表的,没关系增加分钟!
对于图表/图形的基本查询,我需要使用此方法,使用左联接从其他位置提取数据。
谢谢
select * from
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
(select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
(select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
(select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
(select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
(select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where selected_date between '2019-01-01' and '2019-01-15'
当前输出:
selected_date
---
2019-01-01
2019-01-02
2019-01-03
2019-01-04
所需的输出:
selected_date
---
2019-01-19 00:05:00
2019-01-19 00:06:00
2019-01-19 00:07:00
2019-01-19 00:08:00
2019-01-19 00:09:00
2019-01-19 00:10:00
2019-01-19 00:11:00
编辑: 这是我的SQL查询提供图表。我每分钟会得到5-6条温度记录,因此我将它们平均。 我的问题有时是温度探测器脱落,因此a.date_time或b.date_time没有每分钟的连续date_time
select
b.date_time,
a.temperature as fishtank,
b.temperature as room
from (
select
serial,
convert((min(date_time) div 100)*100, datetime) as date_time,
avg(temperature) as temperature
from
raspicontroller.temperature
WHERE
date_time between '$date_from' and '$date_to' and
serial like '28-000898430d59'
group by
date_time div 100
) a
right join (
select
serial,
convert((min(date_time) div 100)*100, datetime) as date_time,
avg(temperature) as temperature
from
raspicontroller.temperature
WHERE
date_time between '$date_from' and '$date_to' and
serial like '28-000f9843201e'
group by
date_time div 100
) b on a.date_time = b.date_time
再次编辑: 我没有设法生成想要的内容,但是我想出了它使用数据库中的现有值来列出日期的方法。我认为这对我有用
SELECT
a.date_time,
b.temperature as FishTank,
c.temperature as Room
FROM (
select
convert((min(date_time) div 100)*100, datetime) as date_time
from
raspicontroller.temperature
group by
date_time div 100
) as a
LEFT JOIN (
select
serial,
convert((min(date_time) div 100)*100, datetime) as date_time,
avg(temperature) as temperature
from
raspicontroller.temperature
WHERE
serial like '28-000898430d59'
group by
date_time div 100
) as b on a.date_time = b.date_time
LEFT JOIN (
select
serial,
convert((min(date_time) div 100)*100, datetime) as date_time,
avg(temperature) as temperature
from
raspicontroller.temperature
WHERE
serial like '28-000f9843201e'
group by
date_time div 100
) as c on a.date_time = c.date_time