如果数组具有相同的键，如何从数组中求值？

Question

我有一系列这样的结果：

Array
(
    [0] => Array
        (
            [product_code] => 1240605
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 20727.3
            [disc_strata] => 20727.3
        )
    [1] => Array
        (
            [product_code] => 1330114
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 20727.3
            [disc_strata] => 20727.3
        )
    [2] => Array
        (
            [product_code] => 1330115
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 20727.3
            [disc_strata] => 20727.3
        )
    [3] => Array
        (
            [product_code] => 1240605
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 10472.64
            [disc_strata] => 10472.64
        )
    [4] => Array
        (
            [product_code] => 1330114
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 10472.64
            [disc_strata] => 10472.64
        )
    [5] => Array
        (
            [product_code] => 1330115
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 10472.64
            [disc_strata] => 10472.64
        )
    [6] => Array
        (
            [product_code] => 1240605
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 2618.16
            [disc_strata] => 2618.16
        )
    [7] => Array
        (
            [product_code] => 1330114
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 2618.16
            [disc_strata] => 2618.16
        )
    [8] => Array
        (
            [product_code] => 1330115
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 2618.16
            [disc_strata] => 2618.16
        )
)

上面，有9个数组结果具有相同的 3个产品代码（1240605、1330114、1330115）

我想要这样的结果：

Array
(
    [0] => Array
        (
            [product_code] => 1240605
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 33818.1
            [disc_strata] => 33818.1
        )
    [1] => Array
        (
            [product_code] => 1330114
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 33818.1
            [disc_strata] => 33818.1
        )
    [2] => Array
        (
            [product_code] => 1330115
            [promo_level] => 2
            [promo_type] => PCN
            [free_value] => 33818.1
            [disc_strata] => 33818.1
        )
)

每次找到相同的产品代码时，都会添加自由值和光盘层。 希望有人可以提供帮助。