how to select date time step by 60 second from first value to last value in table

Question

I want to add 60 seconds to the date value from the first date and return the data if it exists in that interval like this

datetime	value
2021-05-02 12:20:1	5
2021-05-02 12:20:15	8
2021-05-02 12:20:26	12
2021-05-02 12:21:1	63
2021-05-02 12:21:23	90
2021-05-02 12:21:12	73
2021-05-02 12:22:3	39
2021-05-02 12:23:12	3
2021-05-02 12:28:23	74
2021-05-02 12:28:26	38
2021-05-02 12:28:26	72
2021-05-02 12:28:28	12
2021-05-02 12:28:30	69

RESULT like :

datetime	value
2021-05-02 12:20:1	5
2021-05-02 12:21:1	63
2021-05-02 12:22:3	39
2021-05-02 12:23:12	3
2021-05-02 12:28:23	74

I try by this code But I did not get the right Result

        WITH cte AS (
    SELECT *, 
          ROW_NUMBER() OVER (PARTITION BY datetime ORDER BY DATETIME)-  ROW_NUMBER() OVER (PARTITION BY dateadd(second,60,datetime) ORDER BY DATETIME) as g
    FROM Inputs
                    )
                SELECT DateTime
                    FROM cte
                    group by g

Answer 1

You can truncate the date to the minute and partition by that value

WITH cte AS (
    SELECT *,
      ROW_NUMBER() OVER (PARTITION BY DATEADD(minute, DATEDIFF(minute, 0, t.datetime), 0)
        ORDER BY t.datetime) AS rn
    FROM YourTable t
)
SELECT
  datetime,
  value
FROM cte
WHERE rn = 1;