paad/action/action_roles_select.php

<?php
    $ruta = "../";
    require_once "../include/bd_pdo.php";

    global $pdo;

    $sql = "SELECT * FROM rol WHERE rol_id = :idRol";
    $params = [':idRol' => $_POST['rol']];
    
    echo json_encode( query($sql, $params, true));
?>