[
[
"1/1/2018 0:00:00",
1044,
6600168
],
[
"1/1/2018 0:02:52",
975,
4388475
],
[
"1/1/2018 0:05:45",
1020,
6865620
]
]
<?php
include 'pdo.php';
$data = $db->query("SELECT col1, col2, col3 FROM table")->fetchAll(PDO::FETCH_NUM);
echo json_encode($data, JSON_PRETTY_PRINT);