SQL Server 2017

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select @@version;


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Microsoft SQL Server 2017 (RTM-CU21) (KB4557397) - 14.0.3335.7 (X64) 
	Jun 12 2020 20:39:00 
	Copyright (C) 2017 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



CREATE TABLE logs ( name VARCHAR(5), state VARCHAR(5), date DATE );
INSERT INTO logs VALUES
  ( 'A'     , 'X'     , '2021-03-01')
, ( 'A'     , 'X'     , '2021-03-02')
, ( 'A'     , 'X'     , '2021-03-03')
, ( 'A'     , 'Y'     , '2021-03-04')
, ( 'A'     , 'Y'     , '2021-03-05')
, ( 'A'     , 'X'     , '2021-03-06')
, ( 'A'     , 'X'     , '2021-03-07')
, ( 'B'     , 'S'     , '2021-03-01')
, ( 'B'     , 'S'     , '2021-03-02')
, ( 'B'     , 'T'     , '2021-03-03')
, ( 'B'     , 'T'     , '2021-03-04')
, ( 'B'     , 'T'     , '2021-03-05')
, ( 'B'     , 'T'     , '2021-03-06')
, ( 'B'     , 'S'     , '2021-03-07')
;
14 rows affected

WITH cte1 AS (
        SELECT name
             , ROW_NUMBER()      OVER (PARTITION BY name        ORDER BY date)
             - ROW_NUMBER()      OVER (PARTITION BY name, state ORDER BY date) AS n
             , state
             , date
          FROM logs
     )
SELECT name
     , MIN(state) AS state
     , MIN(date)  AS min_date
  FROM cte1
 GROUP BY name, n
 ORDER BY name, min_date
;


name
state
min_date


A
X
2021-03-01

A
Y
2021-03-04

A
X
2021-03-06

B
S
2021-03-01

B
T
2021-03-03

B
S
2021-03-07

name	state	min_date
A	X	2021-03-01
A	Y	2021-03-04
A	X	2021-03-06
B	S	2021-03-01
B	T	2021-03-03
B	S	2021-03-07