如何编码对其成员之一进行分组的关联数组？

Question

如何编码对其成员之一进行分组的关联数组？

$my_array = Array(
// customer 1
    [0] => Array
        (
            [customer_id] => 1
            [cutomer_item] => 7
        )

    [1] => Array
        (
            [customer_id] => 1
            [cutomer_item] => 9
        )
// customer 2            
    [2] => Array
        (
            [customer_id] => 2
            [cutomer_item] => 3
        )

    [3] => Array
        (
            [customer_id] => 2
            [cutomer_item] => 5
        )

);

我想要分组（csv）customers_items ，如：

[
// customer 1
    {
     "customer_id" : "1" // customer id preserved
     "cutomer_items" : "7,9" // customer items imploded with a comma
    }
,
// customer 2
    {
     "customer_id" : "2"
     "cutomer_items" : "3,5"
    }
]

我对这么多数组函数（http://php.net/manual/en/ref.array.php）感到困惑。

Answer 1

这是一个想法：

代码

<?php
    $my_array = array(
        array('customer_id' => 1, 'cutomer_item' => 7),
        array('customer_id' => 1, 'cutomer_item' => 9),
        array('customer_id' => 2, 'cutomer_item' => 3),
        array('customer_id' => 2, 'cutomer_item' => 7),
    );

    sort($my_array);

    $customer = '';
    $gp_array = array();
    $carr = false;
    foreach($my_array as $item) {
        if ($customer!=$item['customer_id']) {
            if ($carr!==false) {
                $carr['customer_items'] = implode(',',$carr['customer_items']);
                $gp_array[] = $carr;
            }
            $carr = array('customer_id'=>$item['customer_id'], 'customer_items' => array());
        }
        $customer = $item['customer_id'];
        $carr['customer_items'][] = $item['cutomer_item'];
    }
    if ($carr!==false) {
        $carr['customer_items'] = implode(',',$carr['customer_items']);
        $gp_array[] = $carr;
    }

    $json = json_encode($gp_array);
    echo $json
?>

输出

  

[{ “CUSTOMER_ID”：1， “customer_items”： “7,9”}，{ “CUSTOMER_ID”：2 “customer_items”： “3,7”}]

Answer 2

你可以在mysql查询中使用group_concat函数。如果你是通过mysql获取结果