如何使用数组作为数据库？

Question

    $travels = [
    0 => ['departure' => 'Paris', 'arrival' => 'Nantes'],
    1 => ['departure' => 'Orleans', 'arrival' => 'Nantes'],
    2 => ['departure' => 'Dublin', 'arrival' => 'Tours'],
    3 => ['departure' => 'Paris', 'arrival' => 'Orleans'],
    4 => ['departure' => 'Paris', 'arrival' => 'Nice'],
    5 => ['departure' => 'Nice', 'arrival' => 'Nantes'],
    6 => ['departure' => 'Nice', 'arrival' => 'Tours'],
    7 => ['departure' => 'Tours', 'arrival' => 'Amboise'],
    8 => ['departure' => 'Nice', 'arrival' => 'Nantes'],
];

So this is my code, I want to use this multiple array as a data base, but there is no queries right?

So, I simply want to get all the arrivals values from one departure, like all the arrivals starting from paris, i've tried many things with foreach loop inside foreachloop and if statments and to use the index array but no chance. Is there any way to do it like a query in mysql.

Would be something like:

"SELECT 'arrival' FROM 'travels' WHERE 'departure' = Paris"

Answer 1

As far as I understood your question, you could do something like this:

$resultArr = [];

array_walk($travels, function($value, $key) use (&$resultArr) {
    if($value['departure'] == 'Paris')
       $resultArr[$key] = $value;
});

This will fill your new array with those departures, that are only from Paris.

Another approach would be the use of array_filter as suggested by mfonda in his answer of a post:

$filtered = array_filter($travels, function($v) { return $v['departure'] == 'Paris'; });

Answer 2

This will get all arrivals with departure 'Paris':

<?php
$travels = [
  0 => ['departure' => 'Paris', 'arrival' => 'Nantes'],
  1 => ['departure' => 'Orleans', 'arrival' => 'Nantes'],
  2 => ['departure' => 'Dublin', 'arrival' => 'Tours'],
  3 => ['departure' => 'Paris', 'arrival' => 'Orleans'],
  4 => ['departure' => 'Paris', 'arrival' => 'Nice'],
  5 => ['departure' => 'Nice', 'arrival' => 'Nantes'],
  6 => ['departure' => 'Nice', 'arrival' => 'Tours'],
  7 => ['departure' => 'Tours', 'arrival' => 'Amboise'],
  8 => ['departure' => 'Nice', 'arrival' => 'Nantes'],
];
foreach ($travels as $key => $value) {
    if ($value['departure'] == 'Paris') {
        echo $value['arrival'];
}
}
?>

This will list all the arrivals, however, if you want to limit to only show the arrival name once, you'll have to add some code.