Question

我有一个由mysql_fetch_assoc填充的数组。在我希望从数据库填充数组之后，我想使用我之前在函数中获得的值向数组中添加另一个键。我尝试使用foreach循环完成此操作，但我的函数没有返回数组。我哪里出错？

//calculates payout 
function calculate_payout($id){
    $result = mysql_query("SELECT `result` FROM `bets` WHERE `id` = {$id}");
    echo mysql_error();
    $wager_total = mysql_query("SELECT SUM(`wager_amount`) AS `wager_total` FROM `wagers` WHERE `id` = '{$id}'");
    $correct_wager_total = mysql_query("SELECT SUM(`wager_amount`) AS `correct_wager_total` FROM `wagers` WHERE `id` = '{$id}' AND `wager_option` = '{$result}'");
    echo mysql_error();
    $incorrect_wager_total = $wager_total - $correct_wager_total;

    $sql = "    SELECT * FROM `wagers` WHERE `id` = '{$id}' AND `wager_option` = '{$result}'";
    echo mysql_error();
    $data = mysql_query($sql);

    $rows = array();
    while(($row = mysql_fetch_assoc($data)) !== false){
        $rows[] = array(
            'bet_id'         => $row['bet_id'],
            'id'             => $row['id'],
            'wager_amount'   => $row['wager_amount']
        );
    }

    foreach ($rows as $p_row){
        $payout = $p_row['wager_amount'] / $incorrect_wager_total;
        $payout = $p_row['wager_amount'] + $payout;
        $p_row['payout'] = $payout;
    }

    return $p_row;
}

Answer 1

问题是$p_row是数组中行的副本，因此在循环中修改它对原始数组没有任何影响。

您可以使用foreach：

中的引用来解决此问题

foreach ($rows as &$p_row)

或者您可以在$rows循环中创建while数组时执行此操作：

while ($row = mysql_fetch_assoc($data)) {
    $new_row = array(
        'bet_id'         => $row['id'],
        'id'             => $row['id'],
        'wager_amount'   => $row['wager_amount'],
        'payout'         => $row['wager_amount'] / $incorrect_wager_total + $row['wager_amount']
    );

另外，你的return语句是错误的，它应该是return $rows;来返回整个数组; return $p_row将返回数组的最后一行。

在函数内添加新的数组键

1 个答案: