<?php
$bdd = new PDO('mysql:host=localhost;dbname=ticket;charset:utf8', 'root', '');

try {
    $reponse = $bdd->query("SELECT * FROM pannes WHERE `" .$_POST['champ'] ."`='" .$_POST['value'] ."'");
    $result = [];
    while ($line = $reponse->fetch()) {
        array_push($result, $line);
    };

    print_r(json_encode($result));
} catch (Exception) {
    echo false;
}
?>