查询以获取所需的表

Question

我在自己的mySQL数据库上有以下查询：

SELECT
    Evento,
    Categoria,
    Medaglia,
    IF (MAX(`1912`) > 0, 'X', '') AS '1912',
    IF (MAX(`1908`) > 0, 'X', '') AS '1908',
    IF (MAX(`1904`) > 0, 'X', '') AS '1904',
    IF (MAX(`1900`) > 0, 'X', '') AS '1900',
    IF (MAX(`1896`) > 0, 'X', '') AS '1896'
FROM
    (
        SELECT 
            Evento, 
            Categoria,
            Medaglia,
            IF (Olimpiade = 1912, 1, 0) AS '1912',
            IF (Olimpiade = 1908, 1, 0) AS '1908',
            IF (Olimpiade = 1904, 1, 0) AS '1904',
            IF (Olimpiade = 1900, 1, 0) AS '1900',
            IF (Olimpiade = 1896, 1, 0) AS '1896'
        FROM Olympics.ItalianAthletes
        WHERE Sport='Athletics' and ItalianAthletes.Medaglia is not null
    ) AS Games
GROUP BY Evento, Categoria
ORDER BY Evento ASC, Categoria ASC

通过此查询，我得到了这个结果：

Evento       Categoria  Medaglia  1912  1908  1904  1900  1896  
-----------  ---------  --------  ----  ----  ----  ----  ----  
10000m Walk  Men        bronze    X                             
800m         Men        silver          X 

我想获得的是以下结果：

Evento       Categoria  1912   1908   1904  1900  1896  
-----------  ---------  ----   ----   ----  ----  ----  
10000m Walk  Men        bronze                             
800m         Men               silver

等等。我怎么能这样做？