MySQL - PILIH hanya 2 baris dari setiap 'grup'

Anda memiliki ide yang tepat. Namun, MySQL tidak menjamin urutan evaluasi ekspresi. Plus, Anda memiliki group by position di subkueri.

Jadi saya rasa Anda mungkin ingin:

SELECT . . .
FROM (SELECT name, surname, position, value, points, 
             (@num := if(@type = position, @num + 1,
                         if(@type := position, 1, 1)
                        )
             ) AS row_number
      FROM players p CROSS JOIN
           (SELECT @num := 0, @type := '') params
      WHERE (name LIKE '%$searchphrase%' OR surname LIKE '%$searchphrase%') AND
            value >= '$minvalue' AND value <= '$maxvalue'
      ORDER BY position
     )  x
WHERE x.row_number <= 2