You can do this more easy way. And 100% works that you want
<?php
$servername = "localhost";
$username = "root";
$password = ""; //your database password
$dbname = "demo"; //your database name
$con = new mysqli($servername, $username, $password, $dbname);
if ($con->connect_error) {
die("Connection failed: " . $con->connect_error);
}
else
{
//echo ("Connect Successfully");
}
$query = "SELECT Date_time, Tempout FROM alarm_value"; // select column
$aresult = $con->query($query);
?>
<!DOCTYPE html>
<html>
<head>
<title>Massive Electronics</title>
<script type="text/javascript" src="loder.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart(){
var data = new google.visualization.DataTable();
var data = google.visualization.arrayToDataTable([
['Date_time','Tempout'],
<?php
while($row = mysqli_fetch_assoc($aresult)){
echo "['".$row["Date_time"]."', ".$row["Tempout"]."],";
}
?>
]);
var options = {
title: 'Date_time Vs Room Out Temp',
curveType: 'function',
legend: { position: 'bottom' }
};
var chart = new google.visualization.AreaChart(document.getElementById('areachart'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="areachart" style="width: 900px; height: 400px"></div>
</body>
</html>
loder.js link here loder.js