SQL using select subquery for date range in where statement to determine the max value in that date range

Question

I am trying to get a the max value per user within a time frame. The date range is determined by the first occurrence by each user within a separate time range and the 2 weeks prior, ie the first time a user shows up in October is 2018-10-01, therefore the range is from 2018-09-18 to 2018-10-01. Within that range, I am looking for the maximum Value of a column. All of this data comes from the same table.

Example:

+------------+------------+---------+
| Profile_ID |    Date    | Value   |
+------------+------------+---------+
|          1 | 2018-10-05 |    100  |
|          2 | 2018-10-02 |     50  |
|          2 | 2018-10-04 |     78  |
|          2 | 2018-10-05 |     56  |
|          1 | 2018-10-08 |    110  |
|          1 | 2018-10-01 |     99  |
|          2 | 2018-09-30 |     88  |
|          1 | 2018-09-27 |    106  |
+------------+------------+---------+

I am looking for the peak VALUE from the two weeks prior to and including the first occurrence after OCT 1. That would be 2018-10-01 for USER 1 and 2018-10-02 for user 2. The peak value would then be 106 and 88, respectively.

I tried to the code:

SELECT max(Value)
FROM table
WHERE Date BETWEEN (
  SELECT (min(Date) - INTERVAL 2 week)
  FROM table
  WHERE stamp between '2018-10-01' AND '2018-10-25'
  GROUP BY profile_id
  )
  AND
  (
  SELECT min(Date)
  FROM table
  WHERE stamp between '2018-10-01' AND '2018-10-25'
  GROUP BY profile_id
  )

I am getting an error:

Syntax Error: at or near "2"

but I think that is just the start of my problems. Does anyone know the best way to find the max value in that time range for each profile_id?

Answer 1

If I understand correctly, you can use row_number() and some date filtering:

select t.*
from (select t.*,
             row_number() over (partition by profile_id order by date desc) as seqnum
      from t
      where date <= '2018-10-01'
     ) t
where seqnum = 1;