每次添加新行时更新列表

Question

I am using PHP to insert data into a DB. I have a table called games and it's defined this way :

ID  |  Score  |  Rank

I want the rank column to be updated everytime a new row is added. Rank column have to sort Games by score.

For example :

ID  |  Score  |  Rank
1   |    5    |   2
2   |    9    |   1

When I add a new row (ID=3, Score=15) my table will be like this :

ID  |  Score  |  Rank
1   |    5    |   3
2   |    9    |   2
3   |   15    |   1

I have tried this in PHP but it dosen't seem to work :

try {
   $bdd->exec("INSERT INTO games(score) VALUES('$score')");
} catch (Exception $e) {
   die ($e->getMessage());
}

try {
       $bdd->exec("UPDATE games set rank=(SELECT @curRank := @curRank + 1 
       AS rank FROM games g, (SELECT @curRank := 0) r
       ORDER BY  score;)");
    } catch (Exception $e) {
       die ($e->getMessage());
    }

Any ideas how can this be done with PHP ? Or is there a way to set the column value by default to be the rank of the scores ?

Answer 1

try {
   $bdd->exec("SET @pos := 0;
   UPDATE games SET rank= ( SELECT @pos := @pos + 1 ) ORDER BY score DESC;)");
} catch (Exception $e) {
   die ($e->getMessage());
}

This worked for me. Thanks anyway.