php - 合并具有相同键的数组的子数组

Question

我正在尝试填充一个数组，其中 room_id 应该组合在一个子数组中，而不是像现在那样分开。这是我的代码:

$query = "SELECT res_id, room_id, guest_id, check_in_date, check_out_date FROM reservation ";

$result = mysqli_query($link, $query) or die (mysqli_error($link));
$rooms = array();
while ($row = mysqli_fetch_assoc($result)) {
    $rooms[] = $row;
}

$array_date = array();

foreach ($rooms as $room) {
    $array_date[] = date_range($room['room_id'], $room['check_in_date'], $room['check_out_date']);
}

function date_range($room_id, $first, $last, $step = '+1 day', $output_format = 'Y-m-d' ) {

    $room_date = array();
    $dates = array();
    $current = strtotime($first);
    $last = strtotime($last);

    while( $current <= $last ) {
        $dates[] = date($output_format, $current);
        $current = strtotime($step, $current);
    }
    $room_date[$room_id] = $dates;

    return $room_date;
}

这是 var_dump 的结果:

Array
(
    [0] => Array
        (
            [1] => Array
                (
                    [0] => 2015-04-08
                    [1] => 2015-04-09
                    [2] => 2015-04-10
                )

        )

    [1] => Array
        (
            [1] => Array
                (
                    [0] => 2015-04-11
                    [1] => 2015-04-12
                    [2] => 2015-04-13
                )

        )

    [2] => Array
        (
            [2] => Array
                (
                    [0] => 2015-04-08
                    [1] => 2015-04-09
                    [2] => 2015-04-10
                    [3] => 2015-04-11
                    [4] => 2015-04-12
                    [5] => 2015-04-13
                )

        )

我真正想要的是这个(相同的 room_id 组合在一个数组中):

Array
(
    [0] => Array
        (
            [1] => Array
                (
                    [0] => 2015-04-08
                    [1] => 2015-04-09
                    [2] => 2015-04-10
                    [3] => 2015-04-11
                    [4] => 2015-04-12
                    [5] => 2015-04-13
                )

        )
    [2] => Array
        (
            [2] => Array
                (
                    [0] => 2015-04-08
                    [1] => 2015-04-09
                    [2] => 2015-04-10
                    [3] => 2015-04-11
                    [4] => 2015-04-12
                    [5] => 2015-04-13
                )
        )
)

我完全没有想法了。如何合并具有相同 room_id 的数组？

Answer 1

我认为第二个示例实际上并不是您想要的结构 - 如果您只是想存储每个房间号的日期，则不需要零索引的第一维度，因此该维度只是碍事。我认为最好的方法是通过引用函数传递现有的子数组，以便它可以直接将元素添加到数组中。我重写了您的代码(并且还删除了一些冗余/低效率)，例如额外的循环，以产生我认为您想要的内容:

$query = "SELECT res_id, room_id, guest_id, check_in_date, check_out_date FROM reservation ";

$result = mysqli_query($link, $query) or die (mysqli_error($link));
$rooms = array();
$array_date = array();

while ($row = mysqli_fetch_assoc($result)) {
    $rooms[] = $row; // This is no longer used, but I'm assuming you want it for something else later

    if (!array_key_exists($row['room_id'], $array_date)) {
        $array_date[$row['room_id']] = array();
        date_range($array_date[$row['room_id']], $row['room_id'], $row['check_in_date'], $row['check_out_date']);
    } else {
        date_range($array_date[$row['room_id']], $row['room_id'], $row['check_in_date'], $row['check_out_date']);
    }
}



function date_range(&$currentDates, $room_id, $first, $last, $step = '+1 day', $output_format = 'Y-m-d' ) {

    $current = strtotime($first);
    $last = strtotime($last);

    while( $current <= $last ) {
        $currentDates[] = date($output_format, $current);
        $current = strtotime($step, $current);
    }
}

这应该产生一个像这样的数组:

Array
(
    [1] => Array // Room ID
    (
        [0] => 2015-04-08
        [1] => 2015-04-09
        [2] => 2015-04-10
        [3] => 2015-04-11
        [4] => 2015-04-12
        [5] => 2015-04-13
    )
    [2] => Array // Room ID
    (
        [0] => 2015-04-08
        [1] => 2015-04-09
        [2] => 2015-04-10
        [3] => 2015-04-11
        [4] => 2015-04-12
        [5] => 2015-04-13
    )
)

因此，您只需执行以下操作即可迭代每个房间的可用日期:

foreach ($array_date as $roomNumber => $dates) {
    foreach ($dates as $date) {
        // Do something
    }
}

此解决方案可能允许重复输入日期，具体取决于表的设置方式。为了避免这些重复，如果房间已被预订，您可以通过替换 while 的内容来检查是否跳过添加日期。循环输入date_range()类似

if (!in_array(date($output_format, $current), $currentDates)) { 
    $currentDates[] = date($output_format, $current);
}

$current = strtotime($step, $current);

希望这是您想要的行为。如果没有请告诉我!