PHP 计算笛卡尔积

Question

我正在研究一个层，该层将数据从多维数组转换为模型以适应遗留 SQL 表。

数据是这样的

array(4) {
  "idnumber" =>
  array(1) {
    [0] =>
    string(6) "123456"
  }
  "names" =>
  array(2) {
    [0] =>
    string(8) "name1"
    [1] =>
    string(8) "name2"
  }
  "keycodes" =>
  array(3) {
    [0] =>
    int(101)
    [1] =>
    int(102)
    [2] =>
    int(103)
  }
}

可以有任意数量的外部元素，也可以有任意数量的内部元素。

我无法想出一种循环遍历它们并生成它的方法（键无关紧要，这只是我对它们进行分组的第一个想法）

array() {
  "123456name1101" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name1"
    [2] =>
    int(101)
  }
  "123456name2101" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name2"
    [2] =>
    int(101)
  }
  "123456name1102" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name1"
    [2] =>
    int(102)
  }
  "123456name2102" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name2"
    [2] =>
    int(102)
  }
  "123456name1103" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name1"
    [2] =>
    int(103)
  }
  "123456name2103" =>
  array(3){
    [0] =>
    string(6) "123456"
    [1] =>
    string(8) "name2"
    [2] =>
    int(103)
  }
}

我该怎么做？

谢谢

Answer 1

下面是一些计算叉积的代码。这不是我的代码，几年前我在网上的某个地方找到它并且从那以后一直在使用它。我不记得它是从哪里来的。

function crossProduct($array1=[], $array2=[], $_=[]) {
    $_ = func_get_args();
    if (count($_) == 0) {
        return array(array());
    }
    $a = array_shift($_);
    $c = call_user_func_array(__FUNCTION__, $_);
    $r = array();
    foreach ($a as $v) {
        foreach ($c as $p) {
            $r[] = array_merge(array($v), $p);
        }
    }
    return $r;
}


$array = array(
  "idnumber" => array("123456"),
  "names" => array("name1", "name2"),
  "keycodes" => array(101, 102, 103)
);

$result = crossProduct($array["idnumber"], $array["names"], $array["keycodes"]);

结果：

Array
(
    [0] => Array
        (
            [0] => 123456
            [1] => name1
            [2] => 101
        )

    [1] => Array
        (
            [0] => 123456
            [1] => name1
            [2] => 102
        )

    [2] => Array
        (
            [0] => 123456
            [1] => name1
            [2] => 103
        )

    [3] => Array
        (
            [0] => 123456
            [1] => name2
            [2] => 101
        )

    [4] => Array
        (
            [0] => 123456
            [1] => name2
            [2] => 102
        )

    [5] => Array
        (
            [0] => 123456
            [1] => name2
            [2] => 103
        )

)

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