php - 如何根据两个键对数组求和(小计)？

Question

我有以下值的数组

 Array
(
    [0] => Array
        (
            [order_date] => 2016-01-01
            [sku] => RK101
            [qty] => 2
        )

    [1] => Array
        (
            [order_date] => 2016-01-01
            [sku] => RK101
            [qty] => 5
        )

    [2] => Array
        (
            [order_date] => 2016-01-01
            [sku] => RK102
            [qty] => 4
        )

    [3] => Array
        (
            [order_date] => 2016-01-02
            [sku] => RK101
            [qty] => 2
        )

    [4] => Array
        (
            [order_date] => 2016-01-02
            [sku] => RK101
            [qty] => 2
        )
)

我想对数组求和，首先按日期，然后按 sku，我想要如下结果

    Array
(
    [2016-01-01] => Array
    (
        [RK101] => Array
        (
            [qty] => 7
        )
        [RK102] => Array
        (
            [qty] => 4
        )
    )
    [2016-01-01] => Array
    (
        [RK101] => Array
        (
            [qty] => 4
        )
    )
)

我探索了堆栈溢出并发现许多帖子基于一个键计算总和，在这种情况下我想先根据日期然后根据 sku 对数组值求和。请帮忙做同样的事情

Answer 1

尝试以下解决方案:

<?php
echo '<pre>';

$array = Array
(
    '0' => Array
    (
        'order_date' => '2016-01-01',
        'sku' => 'RK101',
        'qty' => 2
    ),

    '1' => Array
    (
        'order_date' => '2016-01-01',
        'sku' => 'RK101',
        'qty' => 5
    ),

    '2' => Array
    (
        'order_date' => '2016-01-01',
        'sku' => 'RK102',
        'qty' => 4
    ),

    '3' => Array
    (
        'order_date' => '2016-01-02',
        'sku' => 'RK101',
        'qty' => 2
    ),

    '4' => Array
    (
        'order_date' => '2016-01-02',
        'sku' => 'RK101',
        'qty' => 2
    )
);

$new_array = array();
foreach ($array as $a) {
    if (!isset($new_array[$a['order_date']][$a['sku']]['qty'])) {
        $new_array[$a['order_date']][$a['sku']]['qty'] = 0;
    }
    $new_array[$a['order_date']][$a['sku']]['qty'] += $a['qty'];
}

print_r($new_array);

输出:

Array
(
    [2016-01-01] => Array
        (
            [RK101] => Array
                (
                    [qty] => 7
                )

            [RK102] => Array
                (
                    [qty] => 4
                )

        )

    [2016-01-02] => Array
        (
            [RK101] => Array
                (
                    [qty] => 4
                )

        )

)