PHP按值对数组中的数组进行分组

Question

您好，我遇到了一些问题，但我似乎找不到答案。我有一个包含数组的数组，并希望根据字段的相同值将这些子数组分组。这是我的代码，允许我根据值中的数组对数组进行排序。如何根据共享值对结果进行分组？我可能不知道所有的值，因为有些值是基于日期的，我想例如每天/每月分组

if($filter == "ORDER BY TODO_REF DESC"){
$type_sort = 0;
};
if($filter == "ORDER BY TODO_PRIO DESC"){
$type_sort = 2;
};
if($filter == "ORDER BY TODO_DEAD DESC"){
$type_sort = 3;
};

function aasort (&$array, $key) {
$sorter=array();
$ret=array();
reset($array);
foreach ($array as $ii => $va) {
    $sorter[$ii]=$va[$key];
}
asort($sorter);
foreach ($sorter as $ii => $va) {
    $ret[$ii]=$array[$ii];
}
$array=$ret;
}

 aasort($test_array, $type_sort);
print_r($test_array);

当前输出：

priority
Array
 (

[3] => Array
    (
        [0] => 2
        [1] => sdfsdgdfgdfgdfg
        [2] => 3
        [3] => 2013-05-30 13:53:23
    )

[2] => Array
    (
        [0] => 1
        [1] => This must also be done
        [2] => 4
        [3] => 2013-03-28 12:13:34
    )

[1] => Array
    (
        [0] => 1
        [1] => testing this show me 2
        [2] => 5
        [3] => 2029-02-23 17:27:20
    )

[0] => Array
    (
        [0] => 1
        [1] => Do this task and make sure it gets done
        [2] => 5
        [3] => 2013-06-28 12:12:41
    )

)

我想要的是这样的，根据子数组键 2 将它们分成单独的数组：

Array
(
[3] => Array
    (
        [0] => 2
        [1] => sdfsdgdfgdfgdfg
        [2] => 3
        [3] => 2013-05-30 13:53:23
    )

)
Array
(
[2] => Array
    (
        [0] => 1
        [1] => This must also be done
        [2] => 4
        [3] => 2013-03-28 12:13:34
    )

)
Array
(
[1] => Array
    (
        [0] => 1
        [1] => testing this show me 2
        [2] => 5
        [3] => 2029-02-23 17:27:20
    )

[0] => Array
    (
        [0] => 1
        [1] => Do this task and make sure it gets done
        [2] => 5
        [3] => 2013-06-28 12:12:41
    )

)

Answer 1

$array_1 = array();
$array_2 = array();
foreach($test_array as $item) {
  if($item[0] == 1) {
    $array_1[] = $item;
  } elseif($item[0] == 2) {
    $array_2[] = $item;
  }
}
$final_array = array($array_1, $array_2);

必须有更优化的代码，但这应该可以满足您的需求。

Answer 2

array_multisort() 是您所追求的，它将允许您按子数组对主数组进行排序并维护键值链接

我使用下面的方法对一个相当庞大的多维数组进行排序，该数组基于具有许多列和可排序列的表上的排序顺序箭头 asc/desc。它有点乱，但你应该能够遵循它。

if (strlen($_GET['col'])<1) {
                foreach ($dataarray as $key => $row) {
                    $spend[$key]  = $row[6];
                }
                array_multisort($spend, SORT_DESC, $dataarray);
            } else if ($_GET['col']=="spend"){
                foreach ($dataarray as $key => $row) {
                    $spend[$key]  = $row[3];
                }
                if ($_GET['order']=="asc") {
                    array_multisort($spend, SORT_ASC, $dataarray);
                } else {
                    array_multisort($spend, SORT_DESC, $dataarray);
                }
            } else if ($_GET['col']=="name"){
                foreach ($dataarray as $key => $row) {
                    $name[$key]  = $row[1];
                }
                if ($_GET['order']=="asc") {
                    array_multisort($name, SORT_ASC, $dataarray);
                } else {
                    array_multisort($name, SORT_DESC, $dataarray);
                }
            } else if ($_GET['col']=="avg"){
                foreach ($dataarray as $key => $row) {
                    $avg[$key]  = $row[4];
                }
                if ($_GET['order']=="asc") {
                    array_multisort($avg, SORT_ASC, $dataarray);
                } else {
                    array_multisort($avg, SORT_DESC, $dataarray);
                }
            } else if ($_GET['col']=="sites"){
                foreach ($dataarray as $key => $row) {
                    $sites[$key]  = $row[5];
                }
                if ($_GET['order']=="asc") {
                    array_multisort($sites, SORT_ASC, $dataarray);
                } else {
                    array_multisort($sites, SORT_DESC, $dataarray);
                }
            } else if ($_GET['col']=="rate"){
                foreach ($dataarray as $key => $row) {
                    $rate[$key]  = $row[6];
                }
                if ($_GET['order']=="asc") {
                    array_multisort($rate, SORT_ASC, $dataarray);
                } else {
                    array_multisort($rate, SORT_DESC, $dataarray);
                }
            } else {
                foreach ($dataarray as $key => $row) {
                    $spend[$key]  = $row[2];
                }
                array_multisort($spend, SORT_DESC, $dataarray);
            }

Answer 3

1. 而不是if-elseif-elseif-elseif...else 条件块来确定排序/分组列，我总是推荐一个查找数组，然后是一个非常快速的isset() 调用。我发现这种语法更简洁、更易读、更易于维护。
2. 为了对分组数据进行正确排序，请提前对数据进行排序（当它仍处于其更简单的形式时）。 usort() 与宇宙飞船操作员 (php7) 将为您完成所有艰苦的工作。请务必使用use 将$groupsort 变量传递到函数范围内。
3. 在迭代输入数组时，隔离标识列值（并根据需要准备），然后将其用作临时键来确定应存储$row 数据的组。
4. 最后，使用array_values() 删除临时标识键（如果需要）。

代码：(Demo)

$filter = "ORDER BY TODO_PRIO DESC";
$lookup = [
    "ORDER BY TODO_REF DESC" => 0,
    "ORDER BY TODO_PRIO DESC" => 2,
    "ORDER BY TODO_DEAD DESC" => 3
];
$groupsort = isset($lookup[$filter]) ? $lookup[$filter] : 0;  

$array = [
    [1, "Do this task and make sure it gets done", 5, "2013-06-28 12:12:41"],
    [1, "testing this show me 2", 5, "2029-02-23 17:27:20"],
    [1, "This must also be done", 4, "2013-03-28 12:13:34"],
    [2, "sdfsdgdfgdfgdfg", 3, "2013-05-30 13:53:23"],
    [2, "Another priority", 3, "2013-03-28 11:11:11"]
];

// sort DESC on $groupsort column values
usort($array, function($a, $b)use($groupsort) { return $b[$groupsort] <=> $a[$groupsort]; }); 

// group by $groupsort column values
foreach ($array as $row) {
    $id = $row[$groupsort];                             // just to improve readability
    if ($groupsort == 3) { $id = substr($id, 0, 10); }  // remove time from datetime stamp
    $result[$id][] = $row;                              // store the current value
}

var_export(array_values($result));                      // reindex first level (remove temp keys);

输出：

array (
  0 => 
  array (
    0 => 
    array (
      0 => 1,
      1 => 'Do this task and make sure it gets done',
      2 => 5,
      3 => '2013-06-28 12:12:41',
    ),
    1 => 
    array (
      0 => 1,
      1 => 'testing this show me 2',
      2 => 5,
      3 => '2029-02-23 17:27:20',
    ),
  ),
  1 => 
  array (
    0 => 
    array (
      0 => 1,
      1 => 'This must also be done',
      2 => 4,
      3 => '2013-03-28 12:13:34',
    ),
  ),
  2 => 
  array (
    0 => 
    array (
      0 => 2,
      1 => 'sdfsdgdfgdfgdfg',
      2 => 3,
      3 => '2013-05-30 13:53:23',
    ),
    1 => 
    array (
      0 => 2,
      1 => 'Another priority',
      2 => 3,
      3 => '2013-03-28 11:11:11',
    ),
  ),
)