如果找到总和值，则搜索重复项

我有这个数组：

$data = [
    0 => [
       'date'       => '2018-09-12',
       'department' => 12,
       'country'    => 14,
       'total'      => 12
    ],
    1 => [
       'date'       => '2018-09-12',
       'department' => 12,
       'country'    => 14,
       'total'      => 18
    ],
    2 => [
       'date'       => '2018-09-12',
       'department' => 12,
       'country'    => 15,
       'total'      => 10
    ]
];

返回应该是：

$return = [
   0 => [
       'date'       => '2018-09-12',
       'department' => 12,
       'country'    => 14,
       'total'      => 30
   ],
   1 => [
       'date'       => '2018-09-12',
       'department' => 12,
       'country'    => 15,
       'total'      => 10
   ]
];

我尝试这样：

foreach ($data as $value) {
     if(!in_array($value, $data)) {
         $result[] = $data;
     }
}

这个想法是，如果除总计之外的所有字段都相同，则将总计添加到具有相同字段的现有总计中。请帮我。提前谢谢，抱歉我的英语

您可以通过循环数组、比较每个元素的所有其他值来完成此操作（date, department and country) 与之前看到的值并在获得匹配时将总数相加。这段代码使用serialize生成其他值的复合键以进行比较：

$output = array();
$keys = array();
foreach ($data as $value) {
    $total = $value['total'];
    unset($value['total']);
    $key = serialize($value);
    if (($k = array_search($key, $keys)) !== false) {
        $output[$k]['total'] += $total;
    }
    else {
        $keys[] = $key;
        $output[] = array_merge($value, array('total' => $total));
    }
}
print_r($output);

Output:

Array (
    [0] => Array (
        [date] => 2018-09-12
        [department] => 12
        [country] => 14
        [total] => 30 
    )
    [1] => Array (
        [date] => 2018-09-12
        [department] => 12
        [country] => 15
        [total] => 10
     ) 
)

3v4l.org 上的演示

通过使用复合键作为索引$output数组，我们可以简化这段代码，我们只需要使用array_values循环后重新索引$output array:

$output = array();
foreach ($data as $value) {
    $v = $value;
    unset($v['total']);
    $key = serialize($v);
    if (isset($output[$key])) {
        $output[$key]['total'] += $value['total'];
    }
    else {
        $output[$key] = $value;
    }
}
$output = array_values($output);
print_r($output);

输出与之前相同。3v4l.org 上的演示