获取一个时间范围在另一个时间范围之间的所有出现

Question

我有一个设置了日期以及开始和结束时间的数据库

date	start	end
2021-12-04	10:15:00	13:05:00
2021-12-04	12:18:00	15:38:00
...	...	...

这张桌子可以节省人们进出的时间。

对于一个统计数据，我想获取每小时打卡的人数

例如，如果我指定日期“2021-12-04”，表格应如下所示：

hour	people
10:00-10:59	1
11:00-11:59	1
12:00-12:59	2
13:00-13:59	2
14:00-14:59	1
15:00-15:59	1

我一直在尝试一些查询，我得到的表格在一小时内正确返回了数字，但是一旦涉及到每个小时有人打卡，我似乎无法找到按预期工作的解决方案

Answer 1

带小时生成器：

select hour, count(date) as people
from (select concat(lpad(@num:=@num+1,2,'0'),':00-',lpad(@num,2,'0'),':59') as hour
    from information_schema.tables t1,
        (select @num:=-1) tmp
        limit 24) a
left join table1 b
    on  substr(a.hour,1,2) >= substr(b.start,1,2)
    and substr(a.hour,1,2) <= substr(b.end,1,2)
group by 1

或每小时检查一次，结合联合：

select '00:00-00:59' as hour, count(date) as people from table1
 where '00' between substr(start,1,2) and substr(end,1,2) union
select '01:00-01:59' as hour, count(date) as people from table1
 where '01' between substr(start,1,2) and substr(end,1,2) union
select '02:00-02:59' as hour, count(date) as people from table1
 where '02' between substr(start,1,2) and substr(end,1,2) union
select '03:00-03:59' as hour, count(date) as people from table1
 where '03' between substr(start,1,2) and substr(end,1,2) union
select '04:00-04:59' as hour, count(date) as people from table1
 where '04' between substr(start,1,2) and substr(end,1,2) union
select '05:00-05:59' as hour, count(date) as people from table1
 where '05' between substr(start,1,2) and substr(end,1,2) union
select '06:00-06:59' as hour, count(date) as people from table1
 where '06' between substr(start,1,2) and substr(end,1,2) union
select '07:00-07:59' as hour, count(date) as people from table1
 where '07' between substr(start,1,2) and substr(end,1,2) union
select '08:00-08:59' as hour, count(date) as people from table1
 where '08' between substr(start,1,2) and substr(end,1,2) union
select '09:00-09:59' as hour, count(date) as people from table1
 where '09' between substr(start,1,2) and substr(end,1,2) union
select '10:00-10:59' as hour, count(date) as people from table1
 where '10' between substr(start,1,2) and substr(end,1,2) union
select '11:00-11:59' as hour, count(date) as people from table1
 where '11' between substr(start,1,2) and substr(end,1,2) union
select '12:00-12:59' as hour, count(date) as people from table1
 where '12' between substr(start,1,2) and substr(end,1,2) union
select '13:00-13:59' as hour, count(date) as people from table1
 where '13' between substr(start,1,2) and substr(end,1,2) union
select '14:00-14:59' as hour, count(date) as people from table1
 where '14' between substr(start,1,2) and substr(end,1,2) union
select '15:00-15:59' as hour, count(date) as people from table1
 where '15' between substr(start,1,2) and substr(end,1,2) union
select '16:00-16:59' as hour, count(date) as people from table1
 where '16' between substr(start,1,2) and substr(end,1,2) union
select '17:00-17:59' as hour, count(date) as people from table1
 where '17' between substr(start,1,2) and substr(end,1,2) union
select '18:00-18:59' as hour, count(date) as people from table1
 where '18' between substr(start,1,2) and substr(end,1,2) union
select '19:00-19:59' as hour, count(date) as people from table1
 where '19' between substr(start,1,2) and substr(end,1,2) union
select '20:00-20:59' as hour, count(date) as people from table1
 where '20' between substr(start,1,2) and substr(end,1,2) union
select '21:00-21:59' as hour, count(date) as people from table1
 where '21' between substr(start,1,2) and substr(end,1,2) union
select '22:00-22:59' as hour, count(date) as people from table1
 where '22' between substr(start,1,2) and substr(end,1,2) union
select '23:00-23:59' as hour, count(date) as people from table1
 where '23' between substr(start,1,2) and substr(end,1,2)

Answer 2

简洁的 w col1，将与：

select substr(start, 1, 2) as hour
    , count(start) as people
from table1
group by 1
order by 1

以完整的小时符号为例：

select concat(substr(start, 1, 2), ':00-', substr(start, 1, 2), ':59') as hour
    , count(start) as people
from table1
group by 1
order by 1

dbfiddle here (MySQL 8.0.27)