mysqlクエリで複数の行の列の最大セットを見つける

SELECT
  *
FROM
(
  SELECT
    ROW_NUMBER() OVER (PARTITION BY Code ORDER BY Year DESC, Month DESC) AS row_number,
    *
  FROM
    myTable
)
  AS orderedTable
WHERE
  row_number = 1

編集 そして今、MySQLで動作するバージョンの場合...

SELECT
  *
FROM
  myTable
WHERE
  Year * 12 + Month = (SELECT MAX(Year * 12 + Month) FROM myTable AS lookup WHERE Code = myTable.Code)

編集 SQLにアクセスした後、これがより高速であることを確認できます...

WHERE
    Year  = (SELECT MAX(Year)  FROM myTable AS lookup WHERE Code = myTable.Code)
AND Month = (SELECT MAX(Month) FROM myTable AS lookup WHERE Code = myTable.Code AND Year = myTable.Year)