什麼是X總的項目添加到每個項目，而排序在PHP

Question

數組鑑於訂單中佔各行項目的項目的數組的最佳方式：

var_export([[ 
     'order_id' => 1, 
     'driver_id' => 100, 
     'product_id' => 2 
     ], 
     [ 
     'order_id' => 1, 
     'driver_id' => 100, 
     'product_id' => 1 
     ], 
     [ 
     'order_id' => 2, 
     'driver_id' => 50, 
     'product_id' => 1 
     ] 
]); 

有由driver_id進行排序，然後是product_id。是否有可能在排序過程中的附加字段添加到每個項目，以便在年底我有類似：

var_export([[ 
     'order_id' => 2, 
     'driver_id' => 50, 
     'product_id' => 1, 
     'sequence' => '1 of 1' 
     ], 
     [ 
     'order_id' => 1, 
     'driver_id' => 100, 
     'product_id' => 1, 
     'sequence' => '1 of 2' //if easier, this could be 2 of 2 and the one below 1 of 2 as long as they are ordered this way in the array 
     ], 
     [ 
     'order_id' => 1, 
     'driver_id' => 100, 
     'product_id' => 2, 
     'sequence' => '2 of 2' 
     ] 
]); 

凡sequence顯示訂單中的項目的迭代次數（ORDER_ID 1在兩個項目所以每個應該有一個序列x爲2，但是在訂單內哪個項目標記爲1，哪個項目標記爲2）並不重要。

如果排序時無法做到這一點，那麼添加此字段的最佳方法是什麼？

Answer 1

你可以嘗試這樣的事情：

// Get array of all order ids. 
$orderIds = array_column($array, 'order_id'); 
// Sort $array by order ids. 
array_multisort(
    array_column($array, 'driver_id'), 
    array_column($array, 'product_id'), 
    $orderIds, 
    $array 
); 
// Count order ids occurances. 
$orderIdsCounts = array_count_values($orderIds); 

$counter = 0; 
$array = array_map(function ($orderId, $item) use (&$counter, $orderIdsCounts) { 
    $counter += 1; 

    $item['sequence'] = "$counter of {$orderIdsCounts[$orderId]}"; 

    // Reset the counter if order id total is reached. 
    $counter = $counter === $orderIdsCounts[$orderId] ? 0 : $counter; 

    return $item; 
}, $orderIds, $array); 

這裏是working demo。