這是一個islands and gaps problem 之前我有在一篇文章有分析此問題解法和特徵這裡我就不多敘述了

基本上運用一個簡單算法來分群取得你要的資料

;WITH CTE AS (
SELECT NCode,MIN(DTime) 'minTime',MAX(DTime) 'MaxTime'
FROM (
  SELECT *, ROW_NUMBER() OVER(ORDER BY DTime) - 
            ROW_NUMBER() OVER(PARTITION BY NCode ORDER BY DTime) rn
  FROM da
) t1
GROUP BY rn,NCode
)
SELECT ROW_NUMBER() OVER(ORDER BY minTime) no,*
FROM CTE 

Note:

只要你的dbms可以使用window function都可以使用上面解法

sqlfiddle

select a.*, b.minimun, b.maximum
from
(select distinct [Ncode], [team] from da) a
left join 
(select max([dtime]) as maximum, min([dtime]) as minimun, [ncode], [team] FROM da GROUP BY [ncode], [team]) b
on a.[ncode]=b.[ncode] and a.[team]=b.[team]

http://sqlfiddle.com/#!7/2344d/5/0

with t0(id, dtime, no) as (
select row_number() over(order by dtime, no) 
     , *
  from it210607b
), t1(id, dtime, no, cflag) as (
select *
     , coalesce(no <> lag(no) over(order by id), True)
  from t0
), t2(id, dtime, no, cflag, rn) as (
select *
     , row_number() over(order by id)
  from t1
 where t1.cflag = True
), t3 as (
select t1.*
     , t2.rn
  from t1
  left join t2
    on (t1.id = t2.id)
), t4(dtime, no, grp) as (
select dtime, no
     , max(rn) over(partition by no order by id, rn)
  from t3
)
select grp, no
     , min(dtime)
     , max(dtime)
  from t4
 group by grp, no
 order by grp, no;

 grp | no |         min         |         max
-----+----+---------------------+---------------------
   1 | A  | 2020-05-07 08:44:08 | 2020-05-07 08:44:08
   2 | B  | 2020-05-07 08:45:38 | 2020-05-07 08:47:08
   3 | A  | 2020-05-07 08:47:53 | 2020-05-07 08:48:38
   4 | C  | 2020-05-07 08:49:23 | 2020-05-07 08:49:23
   5 | A  | 2020-05-07 09:44:53 | 2020-05-07 09:44:53
(5 rows)

恩..弄得好複雜@@""

只會用T-SQL

declare @da table
    ([DTime] datetime, [NCode] varchar(10))
;

INSERT INTO @da
    ([DTime], [NCode])
VALUES
    ('2020/05/07 08:44:08', 'A'),
    ('2020/05/07 09:44:53', 'A'),
    ('2020/05/07 08:45:38', 'B'),
    ('2020/05/07 08:46:23', 'B'),
    ('2020/05/07 08:47:08', 'B'),
    ('2020/05/07 08:47:53', 'A'),
    ('2020/05/07 08:48:38', 'A'),
    ('2020/05/07 08:49:23', 'C')

declare @dk table
    ([DTime] datetime, [NCode] varchar(10),Sort int)
;

select no=Identity(int,1,1),* Into #temptable
from @da
declare @Sort int=0,@TmpStr1 nvarchar(50) = '',@TmpStr2 nvarchar(50) = '',@i int = 0,@TotalNum int = 0
select @TotalNum=Count(0) from #temptable
while(@i<@TotalNum)
begin
	set @i = @i + 1
	select @TmpStr1=NCode
	from #temptable
	where no=@i
	if(@TmpStr1<>@TmpStr2)
	begin
		set @TmpStr2 = @TmpStr1
		set @Sort = @Sort + 1
	end
	insert into @dk
	select [DTime]
	,[NCode]
	,@Sort
	from #temptable
	where no=@i
end
Drop Table #temptable

select Sort
,[NCode]
,Min(DTime) Min_DTime
,Max(DTime) Max_DTime
from @dk
group by Sort
,[NCode]
order by Sort

玩一下 ...

CREATE TABLE da
([DTime] datetime, [NCode] varchar(10));

INSERT INTO da ([DTime], [NCode]) VALUES
('2020/05/07 08:44:08', 'A'),
('2020/05/07 08:44:53', 'A'),
('2020/05/07 08:45:38', 'B'),
('2020/05/07 08:46:23', 'B'),
('2020/05/07 08:47:08', 'B'),
('2020/05/07 08:47:53', 'A'),
('2020/05/07 08:48:38', 'A'),
('2020/05/07 08:49:23', 'C');

SELECT PP.No,PP.NCode,MIN(DTime) AS minTime,MAX(DTime) AS MaxTime
FROM (
SELECT M.DTime,M.NCode,1 + SUM(M.Num) OVER (ORDER BY M.DTime) AS No
FROM (
SELECT da.*,
CASE WHEN NCode = LAG(NCode,1,NCode) OVER (ORDER BY DTime) THEN 0 ELSE 1 END AS Num
FROM da) M
) AS PP
GROUP BY PP.No,PP.NCode
ORDER BY PP.No,PP.NCode

Demo