PHP数组将值与相同的字符串键组合起来

Question

我有以下似乎很常见的问题，但不知道哪个数组函数可能适用于以下格式：

（已经尝试过array_merge、array_merge_recursive、array_combine、array_splice，但没有按预期工作。）

Array
(
    [0] => Array
        (
            [r_id] => 11
            [r_sid] => RC
            [d_id] => 2
        )

    [1] => Array
        (
            [r_id] => 7
            [r_sid] => RC
            [c_id] => 51
        )

    [2] => Array
        (
            [r_id] => 6
            [r_sid] => JN
            [c_id] => 52
        )

    [3] => Array
        (
            [r_id] => 7
            [r_sid] => JN
            [c_id] => 51
        )

    [4] => Array
        (
            [r_id] => 7
            [r_sid] => LG
            [c_id] => 51
        )

    [5] => Array
        (
            [r_id] => 7
            [r_sid] => BN
            [c_id] => 51
        )

    [6] => Array
        (
            [r_id] => 6
            [r_sid] => IVS
            [c_id] => 52
        )

    [7] => Array
        (
            [r_id] => 7
            [r_sid] => IVS
            [c_id] => 51
        )

)

现在，我需要通过常见的r_sid & c_id 键合并这个数组值；唯一的特殊情况是如果有一个d_id 键而不是c_id，那么我们将它与数组中具有相似r_sid 的任何值合并/组合。

如果这样更容易理解，最终的解决方案需要如下所示：

Array
(
    [0] => Array
        (
            [r_id] => 11,7
            [r_sid] => RC
            [d_id] => 2
            [c_id] => 51 
        )


    [1] => Array
        (
            [r_id] => 6,7
            [r_sid] => JN, IVS
            [c_id] => 52,51
        )

)

与任何人都不匹配的r_sid 值需要被丢弃。

感谢任何帮助。非常感谢！

Answer 1

这是我对如何合并数组的最佳解释的一段代码：

// filter out r_sid values which only occur once
$sid_values = array_count_values(array_column($array, 'r_sid'));
$array = array_filter($array, function ($a) use ($sid_values) { return $sid_values[$a['r_sid']] > 1; });

// combine arrays on r_sid values
$result = array();
foreach ($array as $arr) {
    $sid = $arr['r_sid'];
    // push data to arrays
    $result[$sid]['r_sid'] = $sid;
    $result[$sid]['r_id'][] = $arr['r_id'];
    if (isset($arr['c_id'])) $result[$sid]['c_id'][] = $arr['c_id'];
    if (isset($arr['d_id'])) $result[$sid]['d_id'][] = $arr['d_id'];
}

// combine all the c_id values into a string
array_walk($result, function (&$a) {
    if (isset($a['c_id'])) $a['c_id'] = implode(',', $a['c_id']);
});

// now combine any r_sid values that have the same set of c_id values
$output = array();
foreach ($result as $res) {
    $cid = $res['c_id'];
    // push data to arrays
    $output[$cid]['c_id'] = $cid;
    $output[$cid]['r_sid'] = array_merge($output[$cid]['r_sid'] ?? array(), array($res['r_sid']));
    $output[$cid]['r_id'] = array_merge($output[$cid]['r_id'] ?? array(), $res['r_id']);
    if (isset($res['d_id'])) $output[$cid]['d_id'] = array_merge($output[$cid]['d_id'] ?? array(), $res['d_id']);
}

// combine the r_sid, r_id and d_id values into a string
array_walk($output, function (&$a) {
    $a['r_sid'] = implode(',', $a['r_sid']);
    $a['r_id'] = implode(',', array_unique($a['r_id']));
    if (isset($a['d_id'])) $a['d_id'] = implode(',', $a['d_id']);
});

// remove the associative keys
$output = array_values($output);

输出：

Array
(
    [0] => Array
        (
            [c_id] => 51
            [r_sid] => RC
            [r_id] => 11,7
            [d_id] => 2
        )
    [1] => Array
        (
            [c_id] => 52,51
            [r_sid] => JN,IVS
            [r_id] => 6,7
        )
)

Demo on 3v4l.org