php - 比较数组数组中的 ID，并在 PHP 中以 desc 顺序仅取一行与日期

Question

我有一个这样的数组：

$data = array (
  0 => 
  array (
    'UserID' => '1',
    'ShipPinCode' => '411008',
    'createdDate' => '2011-10-04 01:16:54.723',
    'Amount' => '1000.00',
  ),
  1 => 
  array (
    'UserID' => '1',
    'ShipPinCode' => '411008',
    'createdDate' => '2011-10-04 01:24:24.243',
    'Amount' => '1000.00',
  ),
  2 => 
  array (
    'UserID' => '102818',
    'ShipPinCode' => '500072',
    'createdDate' => '2011-11-29 12:17:43.880',
    'Amount' => '2000.00',
  ),
  3 => 
  array (
    'UserID' => '100001',
    'ShipPinCode' => '500072',
    'createdDate' => '2011-11-26 11:49:17.760',
    'Amount' => '2000.00',
  ),
);

我想以这样一种方式对其进行排序，即对于 UserID 的重复条目，最终输出应该只包含该 UserID 的一行，其中 createdDate 是最大的，即按降序排列。

期望的输出：

array (
      0 => 
      array (
        'UserID' => '1',
        'ShipPinCode' => '411008',
        'createdDate' => '2011-10-04 01:24:24.243', //only took one row of UserID 1 where the createdDate is the largest.
        'Amount' => '1000.00',
      ),
      1 => 
      array (
        'UserID' => '102818',
        'ShipPinCode' => '500072',
        'createdDate' => '2011-11-29 12:17:43.880',
        'Amount' => '2000.00',
      ),
      2 => 
      array (
        'UserID' => '100001',
        'ShipPinCode' => '500072',
        'createdDate' => '2011-11-26 11:49:17.760',
        'Amount' => '2000.00',
      ),
    );

在这种情况下，我无法弄清楚如何进行比较。我该怎么做？

Answer 1

您可以按升序排序createdDate：

array_multisort(array_column($data, 'createdDate'), SORT_ASC, $data);

然后你可以提取和索引UserID哪个只会保留最后一个：

$result = array_column($data, null, 'UserID');

如果要重新索引（不需要）：

$result = array_values($result);