php - 如何根据php中的日期列对mysql结果数组进行降序排序？

Question

我的母语不是英语，而且是 stackoverflow 的新手，所以如果我做错了什么，请纠正我。我的问题是我从 mysql 数据库名称的两个不同表中检索数据。

1. Event
2. Message

用于获取数据的代码如下。

$msgres=$ticket->getMessages();
$arr1 = array();
while($msg_row_one = db_fetch_array($msgres)){
    $arr1[] = $msg_row_one;
}
$noteres=$ticket->getNotes();
$arr2 = array();
while ($msg_row_two = db_fetch_array($noteres)){
    $arr2[] = $msg_row_two;
}

在此过程之后，我将合并两个数组。

$arr1[]

$arr2[]

像这样。

$merge = array_merge($arr1,$arr2);

然后我得到一个如下所示的数组。

Array
(
    [0] => Array
        (
            [msg_id] => 7563
            [ticket_id] => 1768
            [messageId] => 
            [msg_type] => R
            [message] => this is a link system . this is a link system .
            [staff_id] => 1
            [staff_name] => System Administrator
            [headers] => 
            [source] => staff
            [ip_address] => 10.12.145.174
            [created] => 2016-09-27 01:49:27
            [attachments] => 0
        )

    [1] => Array
        (
            [msg_id] => 7562
            [ticket_id] => 1768
            [messageId] => 
            [msg_type] => R
            [message] => Last message is this.
            [staff_id] => 1
            [staff_name] => System Administrator
            [headers] => 
            [source] => staff
            [ip_address] => 10.12.145.174
            [created] => 2016-09-26 08:39:46
            [attachments] => 0
        )

    [2] => Array
        (
            [msg_id] => 7561
            [ticket_id] => 1768
            [messageId] => 
            [msg_type] => R
            [message] => Last message is this.
            [staff_id] => 1
            [staff_name] => System Administrator
            [headers] => 
            [source] => staff
            [ip_address] => 10.12.145.174
            [created] => 2016-09-26 08:37:25
            [attachments] => 0
        )

    [3] => Array
        (
            [msg_id] => 7558
            [ticket_id] => 1768
            [messageId] => 
            [msg_type] => R
            [message] => mmmmmmmmmmmmmmmmmmmmmmmmmmm
            [staff_id] => 1
            [staff_name] => System Administrator
            [headers] => 
            [source] => staff
            [ip_address] => 10.12.145.174
            [created] => 2016-09-26 07:47:51
            [attachments] => 0
        )
  )

然后我按以下代码对 $merge 数组的日期进行降序排序。

$strdate  = array();
$formated = array();
foreach ($merge as $ascdate){
    $strdate[] = strtotime($ascdate['created']);
}
rsort($strdate);
foreach($strdate as $descdate){
    $formated[] = date('Y-m-d H:i:s',$descdate);
}

现在我想代表日期对整个 $merge 数组进行降序排序。意味着最大的日期 $merge 数组应该排在最前面。我不知道如何在 $merge 数组中应用上述排序日期 $formated。

Answer 1

使用usort对整个数组进行排序，而不仅仅是提取的日期

usort($merge,function ($a,$b) {
      return $a['created'] < $b['created'];
});