排序多维数组的给定索引- PHP

Question

我有两个数组$days_order和$mysql_result，我想用$days_order数组对$mysql_result数组进行排序。我想显示MySQL的结果在天的顺序升序?有没有办法做到这一点或任何其他方式，让我可以通过$days_order在MySQL查询OrderBy部分?

$days_order =  Array([0] => 2[1] => 3[2] => 4[3] => 5 [4] => 6[5] => 7[6] => 1);
$mysql_result = Array (
    [0] => Array
        (
            [hashtag] => a7e87329b5eab8578f4f1098a152d6f4
            [title] => Flower
            [day] => 3
        )
[1] => Array
    (
        [hashtag] => b24ce0cd392a5b0b8dedc66c25213594
        [title] => Free
        [day] => 2
    )
[2] => Array
    (
        [hashtag] => e7d31fc0602fb2ede144d18cdffd816b
        [title] => Ready
        [day] => 1
    )
)

我想在$days_order中排序数组

输出:

  Array
(
  [0] => Array
    (
           [hashtag] => b24ce0cd392a5b0b8dedc66c25213594
           [title] => Free
           [day] => 2
    )
  [1] => Array
        (
            [hashtag] => a7e87329b5eab8578f4f1098a152d6f4
            [title] => Flower
            [day] => 3
        )
  [2] => Array
    (
           [hashtag] => e7d31fc0602fb2ede144d18cdffd816b
           [title] => Ready
           [day] => 1
    )    
)

Answer 1

使用usort自定义比较函数

类似:

usort($ranked, function($a, $b) {
    if ($a['day'] === $b['day']) return 0;
    return ($a['day'] > $b['day']) ? -1 : 1;
});

Answer 2

我使用了以下脚本:

function sort_array_custom_compare($mysql_result,$days_order)
    {
    uasort($mysql_result, function($a,$b) use ($days_order){
        foreach($days_order as $value){
            if($a['day'] == $value){
                return 0;
                break;
            }
            if($b['day'] == $value){
                return 1;
                break;
            }
        }
    });
    return $mysql_result;
    }

Answer 3

您可以在usort的比较函数中use自定义订单数组:

usort($mysql_result, function ($a, $b) use ($days_order) {
    // Then check the position of the 'day' value of each element 
    // against the position of that value in $days_order.
    $a = array_search($a['day'], $days_order);
    $b = array_search($b['day'], $days_order);
    if ($a < $b) return -1;
    if ($a == $b) return 0;
    return 1;
});

如果你想在MySQL中这样做，你可以使用

ORDER BY (`day` + 1) % 7

或者，如果需要比仅仅改变日期更复杂，您可以使用CASE来提供特定的顺序(尽管这个CASE只是做同样的事情):

ORDER BY 
CASE 
    WHEN `day` = 2 THEN 0
    WHEN `day` = 3 THEN 1
    WHEN `day` = 4 THEN 2
    WHEN `day` = 5 THEN 3
    WHEN `day` = 6 THEN 4
    WHEN `day` = 7 THEN 5
    WHEN `day` = 1 THEN 6
END;