函数使用 array_multisort 但不知道如何指定键

Question

对 PHP 很陌生，但找不到相关信息来帮助我。

基本上我正在编写一个函数来从我的 mysql 数据库中获取一天的赛马时间并进行排序。所以我引入了 3 个值 - racedate、racevenue 和 sectional。分段是这样我可以指定我是否想要他们的最后 200 米时间，他们最后 400 米时间等等。

我运行查询，然后把结果放到一个数组中。然后我想按 $sectional.

的值对该数组进行排序

我的问题是创建数组 $times 以使用 array_multisort。我能让它工作的唯一方法是对 'time200' 进行硬编码以指定要排序的内容。我真的希望能够按 $sectional 变量排序，因此我可以对 $sectional 传递的任何类型的列名（即 time200、time400、time600 等）使用此函数。

用 $sectional 而不是 time200 不起作用（这对你更了解你在做什么的人来说很明显）但我不明白为什么。

感谢您的帮助！

  function sectionalrank($racedate, $racevenue, $sectional) {
    global $connection;

    $query   = "SELECT horsename, $sectional ";
    $query  .= "FROM runs ";
    $query  .= "WHERE racedate = '$racedate' ";
    $query  .= "AND venue = '$racevenue' ";
    $query  .= "AND $sectional > 0";

    $result = mysqli_query($connection, $query);

    $array = array();
    while($row = mysqli_fetch_assoc($result)) { 
        $array[] = $row;
    }

    $times = array();
    foreach ($array as $a) {
        $times[] = $a['time200'];
    }

    array_multisort($times, SORT_ASC, $array);

    return $array;

  }

Answer 1

看来你的方法不错。对我有用。

function sectionalrank( $racedate, $racevenue, $sectional )
    {
    // simulate database query
    $racedata[] = array('horsename' => 67, 'time200' => 2, 'time400' => 8);
    $racedata[] = array('horsename' => 86, 'time200' => 1, 'time400' => 3);
    $racedata[] = array('horsename' => 85, 'time200' => 6, 'time400' => 9);
    $racedata[] = array('horsename' => 98, 'time200' => 2, 'time400' => 1);
    $racedata[] = array('horsename' => 86, 'time200' => 6, 'time400' => 6);
    $racedata[] = array('horsename' => 67, 'time200' => 7, 'time400' => 4);

    $array = array();
    foreach ($racedata as $row)
        {
        $array[] = $row;
        }

    $times = array();
    foreach ($array as $a)
        {
        $times[] = $a[$sectional];
        }

    array_multisort($times, SORT_ASC, $array);
    return $array;
    }

// Using $racedata to pass in the data.
echo json_encode( sectionalrank( 'racedate', 'racevenue', 'time200' ) ) . "\n";
echo json_encode( sectionalrank( 'racedate', 'racevenue', 'time400' ) ) . "\n";

Output:
[{"horsename":86,"time200":1,"time400":3},{"horsename":67,"time200":2,"time400":8},{"horsename":98,"time200":2,"time400":1},{"horsename":85,"time200":6,"time400":9},{"horsename":86,"time200":6,"time400":6},{"horsename":67,"time200":7,"time400":4}]
[{"horsename":98,"time200":2,"time400":1},{"horsename":86,"time200":1,"time400":3},{"horsename":67,"time200":7,"time400":4},{"horsename":86,"time200":6,"time400":6},{"horsename":67,"time200":2,"time400":8},{"horsename":85,"time200":6,"time400":9}]

函数使用 array_multisort 但不知道如何指定键

Function using array_multisort but don't know how to specify key

php

function

array-multisort