SQL Server how to update a column for a desired row number

Question

Any idea how I can update a column but only for row number=1 to row number=10 for example?

Answer 1

This uses a derived table to isolate the 10 rows you want to update. Note, they both have an ORDER BY in them to determine the 10 rows

UPDATE
   T
SET
   SomeColumn = @newValue --or constant etc
FROM
   (
   SELECT
      *,
      ROW_NUMBER() OVER (ORDER BY something) AS rn
   FROM
      SomeTable
   WHERE
      ...
   ) T
WHERE
   rn <= 10