SQL Server 2017

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create table Thursday_crypto (
 ID char(6), 
 Level int
)
insert into Thursday_crypto (ID, Level) values 
('ABC001', 1),('ABC001', 2),('ABC001', 3), 
('ABC002', 1),('ABC002', 2)
5 rows affected

select * from Thursday_crypto


ID
Level


ABC001
1

ABC001
2

ABC001
3

ABC002
1

ABC002
2


WITH CTE_DATA AS (
  SELECT [RowNum] = ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Level DESC)
  FROM Thursday_crypto
) 
DELETE 
FROM CTE_DATA
WHERE RowNum > 1
3 rows affected

select * from Thursday_crypto


ID
Level


ABC001
3

ABC002
2