Php 合并两个数组合并相同的数据添加新数据

从数据库检索数据：

$db = array (
    0 => 
    array (
      'stay' => '10',
      'end' => '2015-12-29',
      'start' => '2015-12-20',
      'pid' => '231096236',
      'normal_price' => '385',
      'promo_price' => '385',
      'resell_price' => '385',
    ),
    1 => 
    array (
      'stay' => '7',
      'end' => '2016-01-05',
      'start' => '2015-12-30',
      'pid' => '231096235',
      'normal_price' => '385',
      'promo_price' => '385',
      'resell_price' => '385',
    ),
    2 => 
    array (
      'stay' => '3',
      'end' => '2053-01-01',
      'start' => '2016-01-06',
      'pid' => '231096234',
      'normal_price' => '385',
      'promo_price' => '385',
      'resell_price' => '385',
    ),
  ),

要与之合并的新阵列：

$new = array (
    0 => 
    array (
      'stay' => '2',
      'end' => '2015-07-01',
      'start' => '2015-06-03',
      'normal_price' => '145',
      'promo_price' => '145',
      'resell_price' => '135',
    ),
    1 => 
    array (
      'stay' => '4',
      'end' => '2015-07-05',
      'start' => '2015-07-02',
      'pid' => '231096235',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
    2 => 
    array (
      'stay' => '4',
      'end' => '2015-09-03',
      'start' => '2015-07-06',
      'pid' => '231096236',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
  ),

预期结果：

$expected = array (
    0 => 
    array (
      'stay' => '2',
      'end' => '2015-07-01',
      'start' => '2015-06-03',
      'normal_price' => '145',
      'promo_price' => '145',
      'resell_price' => '135',
    ),
    1 => 
    array (
      'stay' => '4',
      'end' => '2015-07-05',
      'start' => '2015-07-02',
      'pid' => '231096235',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
    2 => 
    array (
      'stay' => '4',
      'end' => '2015-09-03',
      'start' => '2015-07-06',
      'pid' => '231096236',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
    3 => 
    array (
      'stay' => '3',
      'end' => '2053-01-01',
      'start' => '2016-01-06',
      'pid' => '231096234',
      'normal_price' => '385',
      'promo_price' => '385',
      'resell_price' => '385',
    ),
  ),

到目前为止，我的结果是：

$merge = array (
    0 => 
    array (
      'stay' => '2',
      'end' => '2015-07-01',
      'start' => '2015-06-03',
      'normal_price' => '145',
      'promo_price' => '145',
      'resell_price' => '135',
    ),
    1 => 
    array (
      'stay' => '4',
      'end' => '2015-07-05',
      'start' => '2015-07-02',
      'pid' => '231096235',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
    2 => 
    array (
      'stay' => '4',
      'end' => '2015-09-03',
      'start' => '2015-07-06',
      'pid' => '231096236',
      'normal_price' => '100',
      'promo_price' => '100',
      'resell_price' => '100',
    ),
  ),

这些是要求：

若新数组中的记录并没有pid（价格id），那个么它是 被认为是新的数据。（记录开始日期：2015-06-03，结束日期： 2015-06-03）

如果新数组中的记录具有pid并与表中的记录之一匹配，则新记录的值将覆盖旧记录（pid:231096235和pid:231096236的记录）

若数据库中的记录有pid，但与新数组中的任何pid不匹配，则应将其添加到新数组中（它应为pid为231096234的记录）

我的职能：

$merge = array();
foreach ($new as $ikey => $ival) {
    $ispid = (isset($ival['pid'])) ? (int) $ival['pid'] : 0;
    if ($ispid === 0) {
        $merge[] = $ival;
    }
    if ($ispid > 0) {
        $exist = false;
        foreach ($db as $rkey => $rval) {
            $rspid = (int) $rval['pid'];
            if ($ispid === $rspid) {
                $spid_exist = true;
                overridePriceValue($ival, $rval);
                $merge[] = $rval;
            }
        }
//        if ($exist === false) {
//            echo "price id " . $ispid . " is not match with any special prices.";
//        }
    }
}

function overridePriceValue($input_spc_price, &$spc_price) {
    if (isset($input_spc_price['stay'])) {
        $spc_price['stay'] = $input_spc_price['stay'];
    }
    if (isset($input_spc_price['end'])) {
        $spc_price['end'] = $input_spc_price['end'];
    }
    if (isset($input_spc_price['start'])) {
        $spc_price['start'] = $input_spc_price['start'];
    }
    if (isset($input_spc_price['normal_price'])) {
        $spc_price['normal_price'] = $input_spc_price['normal_price'];
    }
    if (isset($input_spc_price['promo_price'])) {
        $spc_price['promo_price'] = $input_spc_price['promo_price'];
    }
    if (isset($input_spc_price['resell_price'])) {
        $spc_price['resell_price'] = $input_spc_price['resell_price'];
    }
}

我需要你的建议来实现这个目标。谢谢：）

您可以使用来自另一个stackoverflow问题的UDF（感谢jwueller），并按如下方式进行操作：

$merge = $new;

foreach($db as $item) {
    if (!in_array_r($item["pid"], $new)) {
        $merge[] = $item;
    }
}

function in_array_r($needle, $haystack, $strict = false) {
    foreach ($haystack as $item) {
        if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) {
            return true;
        }
    }

    return false;
}

---

什么是

$merge=$new，是新的空数组吗？我试过了。