<?php

function dkr($sets)
{
    $result = [];
    for ($i = 0, $count = count($sets); $i < $count - 1; $i++) {
        if ($i == 0) {
            $result = $sets[$i];
        }
        $tmp = [];
        foreach ($result as $res) {
            foreach ($sets[$i + 1] as $set) {
                $tmp[] = $res . $set;
            }
        }
        $result = $tmp;
    }

    return $result;
}

$test = [[1, 2, 3], [4, 5], [7, 8, 9]];

$result = dkr($test);
/**
Array
(
    [0] => 147
    [1] => 148
    [2] => 149
    [3] => 157
    [4] => 158
    [5] => 159
    [6] => 247
    [7] => 248
    [8] => 249
    [9] => 257
    [10] => 258
    [11] => 259
    [12] => 347
    [13] => 348
    [14] => 349
    [15] => 357
    [16] => 358
    [17] => 359
)
**/

print_r($result);

        $a = [1, 2, 3];
        $b = [4, 5];
        $c = [7, 8, 9];
        foreach ($a as $va) {
            foreach ($b as $vb) {
                foreach ($c as $vc) {
                    echo $va . $vb . $vc . "</br>";
                }
            }
        }

三个for循环

YourModel::find()
    ->andWhere(['!=','keyword',''])
    ->andWhere(['is not','keyword',null])
    ->andWhere(['!=','keyword','*'])
    ->All();