Why doesn't this statement update the data in MySQL?

I'm new to MySQL. Whats wrong with this code? It doesn't update data.

"INSERT INTO highscores (name, score, maila, ip)" . "VALUES ('$name', '$score', '$maila', '$ip')" .
"ON DUPLICATE KEY UPDATE score;" . "UPDATE highscores SET (if score>'$score') {score=$score} WHERE name=$name"

This works:

"INSERT INTO highscores (name, score, maila, ip) ".
     "VALUES ('$name', '$score', '$maila', '$ip') " . "
on duplicate key update score = greatest开发者_开发技巧(score, $score)"

Thanks to binaryLV: MSQL: How to overwrite entry only if new one is higher? else create new entry

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When you use ON DUPLICATE KEY UPDATE, you must also specify what to update, that is, in PHP, the right query would be:

$q = "INSERT INTO highscores (name, score, maila, ip) ".
     "VALUES ('$name', '$score', '$maila', '$ip') ".
     "ON DUPLICATE KEY UPDATE score='$score'";