How to fetch latest data(as it is entered) from database automatically to my web page using PHP, AJAX, JQuery?
I used the following code and it is working fine. but I need to fetch and display an updated data on my web page as soon as a new data is entered in my database.
<?php
$hostname = '127.0.0.1';
$username = 'xxxxxxxxxxx';
$password = 'xxxxxxxxxxx';
try {
$dbh = new PDO("mysql:host=$hostname;
dbname=sensor_measurements",
$username, $password);
/*** The SQL SELECT statement ***/
$sth = $dbh->prepare("
SELECT `dtg` AS date,
`temp` AS temperature,
`humid` As humidity,
`acous` As acoustic,
`accel_x` As accelx,
`accel_y` As accely,
`accel_z` As accelz
FROM `sensor_data`
ORDER BY date DESC
LIMIT 1
");
$sth->execute();
/* Fetch all of the remaining rows in the result set */
$result = $sth->fetchAll(PDO::FETCH_ASSOC);
/*** close the database connection ***/
$dbh = null;
}
catch(PDOException $e)
{
echo $e->getMessage();
}
$json_data = json_encode($result);
echo $json_data;
?>
In the js save the last id of the data fetched, then simply compare it. For example create a query in php that only fetches the id, and run it every 5 seconds if the id differs, than fetch the php code that you posted.