MSSQL查询：如何每2小时计算一次（动态）？

Question

我是这个网站的新手，找不到类似的问题，也不确定这是否有可能在SQL中查询，但是，到底是什么，值得一试......

我有一个访问控制系统，它将条目日志写入我的数据库。从我的数据表中附加样本：

tpxID   Rec_Creation_Date
2995392 2018-03-06 11:50:45.000
2995391 2018-03-06 11:39:48.000
2995390 2018-03-06 11:30:58.453
2995389 2018-03-06 11:30:49.297
2995388 2018-03-06 11:30:30.687
2995387 2018-03-06 11:30:22.547
2995386 2018-03-06 11:30:13.483
2995385 2018-03-06 11:30:04.813
2995384 2018-03-06 11:29:57.640
2995383 2018-03-06 11:29:49.670

我的想法是，我想知道是否有2个小时的时间框架，我有超过200个条目？

我的意思是动态查询，不会只查看整个小时。

不仅要查询11：00-13：00，还要查询11：01-13：01和11：02-13：02等...

提前致谢。

Answer 1

select t1.dt, count(*) as cnt 
from table t1 
join table t2 
  on t2.dt > t1.dt 
 and datediff(mi, t1.dt, t2.dt) < 120 
group by t1.dt 
having count(*) > 200

Answer 2

我们可以使用CTE和GROUP BY与HAVING这个 -

declare @xyz table (id int identity(1,1),tpxID int,Rec_Creation_Date datetime)

insert into @xyz (tpxID, Rec_Creation_Date)
select 2995392, '2018-03-06 11:50:45.000' union all
select 2995391, '2018-03-06 11:39:48.000' union all
select 2995390, '2018-03-06 11:30:58.453' union all
select 2995389, '2018-03-06 11:30:49.297' union all
select 2995388, '2018-03-06 11:30:30.687' union all
select 2995387, '2018-03-06 11:30:22.547' union all
select 2995386, '2018-03-06 11:30:13.483' union all
select 2995385, '2018-03-06 11:30:04.813' union all
select 2995384, '2018-03-06 11:29:57.640' union all
select 2995383, '2018-03-06 11:29:49.670' union all
select 2995383, '2018-03-06 09:29:49.670'

;with cte as (
    select
        x.Rec_Creation_Date as StartDT,
        y.Rec_Creation_Date as EndDT
    from @xyz as x
    inner join @xyz as y on x.Rec_Creation_Date < y.Rec_Creation_Date
    where datediff(HOUR,x.Rec_Creation_Date, y.Rec_Creation_Date) >= 2
)
select
    cte.StartDT,
    cte.EndDT
from cte
inner join @xyz as x on x.Rec_Creation_Date between cte.StartDT and cte.EndDT
group by cte.StartDT , cte.EndDT
having count(*) > 200
order by cte.StartDT , cte.EndDT