<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['line']});
google.charts.setOnLoadCallback(drawChart);

function drawChart() {

  var data = new google.visualization.DataTable();
  data.addColumn('timeofday', 'Time');
  data.addColumn('number', 'SO2');
  data.addColumn('number', 'O2');
  data.addColumn('number', 'VOC');

  data.addRows([
<?php
$servername = "localhost";
$username = "root";
$password = "shhhhhhhhhhhhhh";
$dbname = "enb355";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT * FROM aqs";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
  // output data of each row
  while($row = $result->fetch_assoc()) {
    //Echo the format here.
  }
} else {
  echo "0 results";
}

$conn->close();
?>