How to sort the id users that have the maximum of a property?
To get a single row with a maximum value in MySQL you can simply use LIMIT:

SELECT *
FROM `Angriff` 
ORDER BY Metall DESC
LIMIT 1;


if there are multiple rows with the same maximum this will return only one randomly.

To get all rows with the same maximum you can modify your query to use a Correlated Subquery:

SELECT * FROM `Angriff` AS t1
WHERE NOT EXISTS  -- there's no row with a higher `Metall`
  (  SELECT * FROM `Angriff` AS t2
     WHERE t2.Metall &gt; I1.METALL );


A more common way in Standard SQL:

SELECT * FROM `Angriff`
WHERE Metall = 
  (  SELECT MAX(Metall) FROM `Angriff` );