Detect future duplicate values while iterating through MySQL results in PHP

Question

I am trying to calculate a ranking of a team in an ordered MySQL result set, and the issue I\'m having is detecting ties for the first team to show up with the tied

Answer 1

This question has been answered here.

The query:

SELECT a.team_id, a.wins, count(*) instances
FROM
    (SELECT
        s1.team_id,
        sum(s1.score>s2.score) wins
    FROM scoreboard s1
        LEFT JOIN scoreboard s2
            ON s1.year=s2.year
            AND s1.week=s2.week
            AND s1.playoffs=s2.playoffs
            AND s1.game_id=s2.game_id
            AND s1.location<>s2.location
    GROUP BY s1.team_id) AS a
    LEFT JOIN
        (SELECT
            sum(s1.score>s2.score) wins
        FROM scoreboard s1
            LEFT JOIN scoreboard s2
                ON s1.year=s2.year
                AND s1.week=s2.week
                AND s1.playoffs=s2.playoffs
                AND s1.game_id=s2.game_id
                AND s1.location<>s2.location
        GROUP BY s1.team_id) AS b
            ON a.wins = b.wins
GROUP BY a.team_id, b.wins
ORDER BY a.wins DESC;

This gives the output...

=================================
|team_id   | wins    |instances |
=================================
|10        | 44      |1         |
|2         | 42      |3         | //tie
|9         | 42      |3         | //tie
|5         | 42      |3         | //tie
|3         | 41      |1         |
|11        | 40      |1         |
|...       |         |          |
=================================

Then, in PHP, I'll be able to detect all ties by checking when $row['instances'] > 1.

Answer 2

$exists = array();
if ($row['team_id'] == $team_id && !in_array($row['pts'], $exists)) { //current team in resultset matches team in question, set team's rank
        $exists[] = $row['pts'];
        $arr_ranks['tp']['cat'] = 'Total Points';
        $arr_ranks['tp']['actual'] = number_format($row['pts'],1);
        $arr_ranks['tp']['league_rank'] = $rnk;
        $arr_ranks['tp']['div_rank'] = $div_rnk;
    }

Answer 3

I like Ignacio's link to his answer. But if you still wanted to use PHP, you could collect the ranks by SCORE and assign teams to each score. It's probably not the most efficient way to do it, but it would work.

$ranks = array();
while ($row = mysql_fetch_assoc($result)) {
    $ranks[$row['pts']][] = $row['team_id'];
}

$ranks would be an array that could look like...

$ranks[89] = array(1);
$ranks[87] = array(2);
$ranks[76] = array(3,4);
$ranks[52] = array(5);

Use a foreach on $ranks, and double check which way the points would come up (ascending or descending). You can use count() to see if there's a tie.