call_user_func_array with array_multisort

Question

我有排序方向的问题。我尝试用方向对多维数组进行排序。我不能直接使用array_multisort()，因为我不知道会有多少个参数。我使用call_user_func_array('array_multisort', $params);，它可以工作，但我不能设置排序方向（SORT_ASC,SORT_DESC）。如何设置call_user_func_array('array_multisort', $params);的排序方向？这是我的代码，你可以试试

function get_fields($data, $order_by) {
    $order_row = preg_split("/[s,]+/", $order_by);
    for ($i=0;$i<count($order_row);$i++) {
        foreach ($data as $key => $row) {
          $tmp[$i][$key]  = $row[$order_row[$i]];      
        }
    }
    return $tmp;
}
function ordering($data, $order_by) {
    $tmp = get_fields($data, $order_by);
    $params = array();
    foreach($tmp as &$t){
        $params[] = &$t;
    }
    $params[1] = array("SORT_DESC","SORT_DESC","SORT_DESC","SORT_DESC"); // like that no warning but no sorting
    $params[] = &$data;
    call_user_func_array('array_multisort', $params);
    return array_pop($params);
}
$data = array (
    array('id' => 1,'name' => 'Barack','city' => 9),
    array('id' => 7,'name' => 'boris','city' => 2),
    array('id' => 3,'name' => 'coris','city' => 2),
    array('id' => 3,'name' => 'coris','city' => 2)
);
$order_by = "city desc, name";
echo "<br>ORDER BY $order_by<br>";
$ordered = ordering($data, $order_by);
echo "<pre>";
var_dump($ordered);
echo "</pre>";

我想做一个类似MySQL ORDER BY city DESC, name的排序。这是我的目标。

Answer 1

要能够对数组进行多次排序并获得类似ORDER BY city DESC, name ASC的结果，您需要一个进行稳定排序的函数。
据我所知，PHP没有，所以你必须用类似的比较器函数对它进行一次排序

$data = array (
    array('id' => 3,'name' => 'coris','city' => 2),
    array('id' => 1,'name' => 'Barack','city' => 9),
    array('id' => 7,'name' => 'boris','city' => 2),
    array('id' => 3,'name' => 'coris','city' => 2),
);
$order_by = array(
    'city' => array('dir' => SORT_DESC, 'type' => SORT_NUMERIC),
    'name' => array('dir' => SORT_ASC, 'type' => SORT_STRING),
);
function compare($row1,$row2) {
    /* this function should determine which row is greater based on all of the criteria
       and return a negative number when $row1 < $row2
                  a positive number when $row1 > $row2
                  0 when $row1 == $row2
    */
    global $order_by;
    foreach($order_by as $field => $sort) {
        if($sort['type'] != SORT_NUMERIC) {
            // strings are compared case insensitive and assumed to be in the mb_internal_encoding
            $cmp = strcmp(mb_strtolower($row1[$field]), mb_strtolower($row2[$field]));
        } else {
            $cmp = doubleval($row1[$field]) - doubleval($row2[$field]);
        }
        if($sort['dir'] != SORT_ASC) $cmp = -$cmp;
        if($cmp != 0) return $cmp;
    }
    return 0;
}

usort($data,'compare');

Answer 2

我也遇到了同样的问题。似乎call_user_func_array（）无法处理常量。我已经通过动态构建一个参数字符串并评估这个字符串来解决这个问题：

$args  = array($arr1, $arr2);
$order = array(SORT_ASC, SORT_DESC);
$evalstring = '';
foreach($args as $i=>$arg){
    if($evalstring == ''){ $evalstring.= ', '; }
    $evalstring.= '$arg';
    $evalstring.= ', '.$order[$i];
}
eval("array_multisort($evalstring);");

我知道eval（）是邪恶的，这不是一种干净的方式，但它有效；-）

Answer 3

它对我有效：

$arrayThatNeedToSort = array('data..');
$multiSortprop = array(['data.....']=> SORT_DESC,['data.....'] => SORT_ASC)
$properties = array();
foreach ($multiSortprop as $sortArr => $sortArg) {
         array_push($properties,$sortArr);
         array_push($properties,$sortArg);
 }
array_push($properties,$arrayThatNeedToSort);
array_multisort(...$properties);
var_dump(end($properties));