PHP check variable change

[benhowdle89]

Hi,

What i have is a variable that is getting updated periodically and i've set the php script to refresh itself every 30 seconds to run a mysql query updating a db, this is good but if this value isnt changing from the source i get duplicate records in the db, how do i check the value of the variable with php and only execute the query when the variable has changed value?

Thanks

[rajarajan07]

Before generating the next value set your variable to clear or NULL after updating the db, and before updating check whether variable is clear or NULL skip the update process.

[raju_boini525]

post your code.

[benhowdle89]

That sounds perfect, would you mind putting a bit of sample code together please?

This is my code so far:

<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;

	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");

    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
		
?>

So i'm guessing i would need to put some sort of "if" statement above the mysql query??

Thanks

[rajarajan07]

<?php
header('refresh:30; url=pachube.php');
require_once( '/pachube_php_library/pachube_functions.php' );
$api_key = "xxxxxxxxxxxxxxxxx";
$pachube = new Pachube($api_key);
$feed = xxxxx;
$data = $pachube->retrieveData ( $feed, "csv" );
$array = explode(',', $data, 5);
$value = $array[0];
echo $value;
if (isset($value) && !empty($value) && $value != NULL)
{
	//Connect to database
	$opendb = mysql_connect("localhost", "root", "") or mysql_error("Could not connect to database");
    mysql_select_db("test");
    if ($opendb)
		{
     	mysql_query(" INSERT INTO arduino (data) VALUES ($value)");
		mysql_close($opendb);
		}
	$value = '';
} else echo "No value is set";
?>

[benhowdle89]

Brilliant, Thanks so much!!!

[rajarajan07]

Always welcome! Please mark the thread as solved.