Sql query to return one single record per each combination in a table

Question

I need the result for every combination of (from_id, to_id) which has the minimun value and the loop matching a criteria.

So basically I need the loop that has the minim

Answer 1

Can't you do this a lot more simply?

SELECT
  from_id,
  to_id,
  MIN(value)
FROM
  myresults
WHERE
  loop_id % 2 = 0
GROUP BY
  from_id,
  to_id

Or maybe I'm misunderstanding the question.

EDIT: To include loop_id

SELECT
  m2.from_id,
  m2.to_id,
  m2.value,
  m2.loop_id
FROM
  myresults m2 INNER JOIN
    (SELECT
      m1.from_id,
      m1.to_id,
      MIN(m1.value)
    FROM
      myresults m1
    WHERE
      m1.loop_id % 2 = 0
    GROUP BY
      m1.from_id,
      m1.to_id) minset
  ON
        m2.from_id = minset.from_id
    AND m2.to_id = minset.to_id
    AND m2.value = minset.value